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Optimal Calibration-Free Observable for the Nucleon-Coupling Ratio in a Dual-Alkali Comagnetometer for Dark Matter Searches
Authors:
Yossi Rosenzweig,
Yevgeny Kats,
Eli Sarid,
Menachem Givon,
Yonathan Japha,
Ron Folman
Abstract:
A dual-alkali single-cell $^{87}$Rb-$^{39}$K-$^{3}$He comagnetometer can read an axionlike dark matter signal through two optical-rotation channels, encoding the ratio $\mathcal{R}=ξ_n/ξ_p$ of the field's neutron and proton spin couplings in their relative response. The inter-species phase difference $Δ\varphi$ has been proposed as a calibration-free readout that is sensitive to $\mathcal{R}$. Tre…
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A dual-alkali single-cell $^{87}$Rb-$^{39}$K-$^{3}$He comagnetometer can read an axionlike dark matter signal through two optical-rotation channels, encoding the ratio $\mathcal{R}=ξ_n/ξ_p$ of the field's neutron and proton spin couplings in their relative response. The inter-species phase difference $Δ\varphi$ has been proposed as a calibration-free readout that is sensitive to $\mathcal{R}$. Treating the extraction of $\mathcal{R}$ as a statistical estimation problem, we show that the optimal observable is the complex inter-channel ratio, which splits into $Δ\varphi$ and an amplitude ratio, of which only $Δ\varphi$ is insensitive to the relative gain and hence calibration-free. For our choice of comagnetometer parameters, above $\sim\!100$ Hz the phase difference alone captures most of the coupling-ratio information. At lower frequencies $Δ\varphi$ is not near-sufficient: there the amplitude ratio would improve the precision on $\mathcal{R}$ by a factor of $\gtrsim2$ below $\sim\!40$ Hz. Recovering that information, however, requires the relative gain to be known sufficiently accurately, so $Δ\varphi$ stays the robust observable even where it is not the optimal one.
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Submitted 7 August, 2026;
originally announced August 2026.
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Correlated comagnetometry for precision measurements
Authors:
Yossi Rosenzweig,
Yevgeny Kats,
Eli Sarid,
Menachem Givon,
Yonathan Japha,
Ron Folman
Abstract:
Magnetometers are among the most widely used probes in science and technology. Comagnetometers increase sensitivity by self-cancellation of magnetic noise, but only at low frequencies. We suggest a correlated measurement of two alkali species in one cell to cancel the magnetic background also at high frequencies. The inter-species phase difference of the light-matter interaction response function…
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Magnetometers are among the most widely used probes in science and technology. Comagnetometers increase sensitivity by self-cancellation of magnetic noise, but only at low frequencies. We suggest a correlated measurement of two alkali species in one cell to cancel the magnetic background also at high frequencies. The inter-species phase difference of the light-matter interaction response function is found to be calibration free and insensitive to common-mode intensity noise. Utilizing a dark-matter signal as a testcase, the method achieves a thirtyfold background suppression, raising the signal-to-noise ratio by an order of magnitude or more, depending on the coupling to the different subatomic particles. We show that the method also provides model differentiation. The higher sensitivity and model differentiation open a path to novel probes for precision measurements in general and exotic fields in particular.
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Submitted 20 July, 2026;
originally announced July 2026.
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Search for a solar-bound axion halo using the Global Network of Optical Magnetometers for Exotic physics searches
Authors:
Tatum Z. Wilson,
Derek F. Jackson Kimball,
Samer Afach,
Jiexiao Bi,
B. C. Buchler,
Dmitry Budker,
Kaleb Cervantes,
Joshua Eby,
Nataniel L. Figueroa,
Ron Folman,
Jiawei Gao,
Daniel Gavilán-Martín,
Menachem Givon,
Zoran D. Grujić,
Hong Guo,
Paul Hamilton,
M. P. Hedges,
Zhejun Huang,
Dongok Kim,
Younggeun Kim,
Sami S. Khamis,
Emmanuel Klinger,
Abaz Kryemadhi,
Nina Kukowski,
Jianjun Li
, et al. (28 additional authors not shown)
Abstract:
We report on a search for a gravitationally bound solar axion halo using data from the Global Network of Optical Magnetometers for Exotic physics searches (GNOME), a worldwide array of magnetically shielded atomic magnetometers with sensitivity to exotic spin couplings. Motivated by recent theoretical work suggesting that self-interacting ultralight axions can be captured by the Sun's gravitationa…
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We report on a search for a gravitationally bound solar axion halo using data from the Global Network of Optical Magnetometers for Exotic physics searches (GNOME), a worldwide array of magnetically shielded atomic magnetometers with sensitivity to exotic spin couplings. Motivated by recent theoretical work suggesting that self-interacting ultralight axions can be captured by the Sun's gravitational field and thermalize into the ground state, we develop a signal model for the pseudo-magnetic fields generated by axion-proton gradient couplings in such a halo. The analysis focuses on the fifth GNOME Science Run (69 days, 12 stations), employing a cross-correlation pipeline with time-shifted daily modulation templates to search for the global, direction-dependent, monochromatic signal expected from a solar axion halo. No statistically significant candidate signals are observed. We set 95% confidence-level upper limits on the amplitude of the axion-induced pseudo-magnetic field over the frequency range $\approx 0.05-20$ Hz, translating to constraints on the linear and quadratic axion-proton couplings for halo densities predicted by gravitational capture models and for the maximum overdensities allowed by planetary ephemerides. In the quadratic coupling case, our limits surpass existing astrophysical bounds by over two orders of magnitude across much of the accessible parameter space.
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Submitted 1 July, 2026; v1 submitted 10 December, 2025;
originally announced December 2025.
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A Spin-Based Pathway to Testing the Quantum Nature of Gravity
Authors:
Sougato Bose,
Anupam Mazumdar,
Roger Penrose,
Ivette Fuentes,
Marko Toroš,
Ron Folman,
Gerard J. Milburn,
Myungshik Kim,
Adrian Kent,
A. T. M. Anishur Rahman,
Cyril Laplane,
Aaron Markowitz,
Debarshi Das,
Ethan Campos-Méndez,
Eva Kilian,
David Groswasser,
Menachem Givon,
Or Dobkowski,
Peter Skakunenko,
Maria Muretova,
Yonathan Japha,
Naor Levi,
Omer Feldman,
Damián Pitalúa-García,
Jonathan M. H. Gosling
, et al. (30 additional authors not shown)
Abstract:
A key open problem in physics is the correct way to combine gravity (described by general relativity) with everything else (described by quantum mechanics). This problem suggests that general relativity and possibly also quantum mechanics need fundamental corrections. Most physicists expect that gravity should be quantum in character, but gravity is fundamentally different to the other forces beca…
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A key open problem in physics is the correct way to combine gravity (described by general relativity) with everything else (described by quantum mechanics). This problem suggests that general relativity and possibly also quantum mechanics need fundamental corrections. Most physicists expect that gravity should be quantum in character, but gravity is fundamentally different to the other forces because it alone is described by spacetime geometry. Experiments are needed to test whether gravity, and hence space-time, is quantum or classical. We propose an experiment to test the quantum nature of gravity by checking whether gravity can entangle two micron-sized crystals. A pathway to this is to create macroscopic quantum superpositions of each crystal first using embedded spins and Stern-Gerlach forces. These crystals could be nanodiamonds containing nitrogen-vacancy (NV) centres. The spins can subsequently be measured to witness the gravitationally generated entanglement. This is based on extensive theoretical feasibility studies and experimental progress in quantum technology. The eventual experiment will require a medium-sized consortium with excellent suppression of decoherence including vibrations and gravitational noise. In this white paper, we review the progress and plans towards realizing this. While implementing these plans, we will further explore the most macroscopic superpositions that are possible, which will test theories that predict a limit to this.
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Submitted 1 September, 2025;
originally announced September 2025.
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Neutralization of Levitated Charged Nanodiamond: Towards matter-wave interferometry with massive objects
Authors:
Sela Liran,
Or Dobkowski,
Rafael Benjaminov,
Peter Skakunenko,
Michael Averbukh,
Yaniv Bar-Haim,
David Groswasser,
Joshua H. Baraban,
Ron Folman
Abstract:
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle, can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in completely new regimes, as well as the interface between QM and GR, e.g., testing the quantization…
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Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle, can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in completely new regimes, as well as the interface between QM and GR, e.g., testing the quantization of gravity. Consequently, there exists an intensive effort to realize such an interferometer. While several paths are being pursued, we focus on utilizing nanodiamonds as our particle, and a spin embedded in the ND together with Stern-Gerlach forces, to achieve a closed loop in space-time. There is a growing community of groups pursuing this path [1]. We are posting this technical note (as part of a series of seven such notes), to highlight our plans and solutions concerning various challenges in this ambitious endeavor, hoping this will support this growing community.
In this work we demonstrate the neutralization of levitated nanodiamonds using ultraviolet photoemission, and characterize the dependence of this process on both the illumination wavelength and particle size. Furthermore, we demonstrate discrete, single-electron charge manipulation of levitated nanodiamond in a needle Paul trap at a pressure of 0.5\,Torr. Finally, we demonstrate fast neutralization of levitated nanodiamonds, achieving a neutralization rate much faster than the state of the art. As neutralization is crucial to avoid spatial decoherence, this constitutes a significant step towards the realization of a nanodiamond spatial interferometer. We would be happy to make available more details upon request.
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Submitted 21 August, 2025;
originally announced August 2025.
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Quantum control of Nitrogen-Vacancy spin in Diamonds: Towards matter-wave interferometry with massive objects
Authors:
N. Levi,
O. Feldman,
Y. Rosenzweig,
D. Groswasser,
A. Elgarat,
M. Gal-Katizri,
R. Folman
Abstract:
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in previously unexplored regimes. It also opens the possibility of probing the interface between QM and…
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Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in previously unexplored regimes. It also opens the possibility of probing the interface between QM and GR, such as testing the quantization of gravity. Consequently, there exists an intensive effort to realize such an interferometer. While several approaches are being explored, we focus on utilizing nanodiamonds with embedded spins as test particles which, in combination with Stern-Gerlach forces, enable the realization of a closed-loop matter-wave interferometer in space-time. There is a growing community of groups pursuing this path [1]. We are posting this technical note (as part of a series of seven such notes), to highlight our plans and solutions concerning various challenges in this ambitious endeavor, hoping this will support this growing community. Here we present our work on quantum control of a nitrogen-vacancy spin system in bulk diamonds and in levitated diamonds as a step towards Stern-Gerlach interferometry with levitated nanodiamonds. Our simulations show that the current state of the art for spin coherence time in nanodiamonds of a few tens of microseconds, is good enough to enable an SGI spatial splitting on the order of nanometers for an ND composed of 10^7 atoms. We would be happy to make available more details upon request.
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Submitted 21 August, 2025;
originally announced August 2025.
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Design of high-efficiency UHV loading of nanodiamonds into a Paul trap: Towards Matter-Wave Interferometry with Massive Objects
Authors:
Rafael Benjaminov,
Sela Liran,
Or Dobkowski,
Yaniv Bar-Haim,
Michael Averbukh,
Ron Folman
Abstract:
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle, can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in completely new regimes, as well as the interface between QM and GR, e.g., testing the quantization…
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Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle, can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in completely new regimes, as well as the interface between QM and GR, e.g., testing the quantization of gravity. Consequently, there exists an intensive effort to realize such an interferometer. While several paths are being pursued, we focus on utilizing nanodiamonds as our particle, and a spin embedded in the ND together with Stern-Gerlach forces, to achieve a closed loop in space-time. There is a growing community of groups pursuing this path [1]. We are posting this technical note (as part of a series of seven such notes), to highlight our plans and solutions concerning various challenges in this ambitious endeavor, hoping this will support this growing community. In this work, we review current methods for loading nanodiamonds into a Paul trap, and their capabilities and limitations regarding our application. We also present our experiments on loading and launching nanodiamonds using a vibrating piezoelectric element and by electrical forces. Finally, we present our design of a novel nanodiamond loading method for ultra-high-vacuum experiments. As the production of highly accurate, high-purity nanodiamonds with a single NV required for interferometric measurements is expected to be expensive, we put emphasis on achieving high loading efficiency, while loading the charged ND into a Paul trap in ultra-high vacuum.
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Submitted 20 August, 2025;
originally announced August 2025.
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Trapping and cooling of nanodiamonds in a Paul trap under ultra-high vacuum: Towards matter-wave interferometry with massive objects
Authors:
Omer Feldman,
Ben Baruch Shultz,
Maria Muretova,
Or Dobkowski,
Yonathan Japha,
David Grosswasser,
Ron Folman
Abstract:
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in previously unexplored regimes. It also opens the possibility of probing the interface between QM and…
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Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in previously unexplored regimes. It also opens the possibility of probing the interface between QM and GR, such as testing the quantization of gravity. Consequently, there exists an intensive effort to realize such an interferometer. While several approaches are being explored, we focus on utilizing nanodiamonds with embedded spins as test particles which, in combination with Stern-Gerlach forces, enable the realization of a closed-loop matter-wave interferometer in space-time. There is a growing community of groups pursuing this path [1]. We are posting this technical note (as part of a series of seven such notes), to highlight our plans and solutions concerning various challenges in this ambitious endeavor, hoping this will support this growing community. In this work we detail the trapping of a nanodiamond at 10^-8 mbar, which is good enough for the realization of a short-duration Stern-Gerlach interferometer. We describe in detail the cooling we have performed to sub-Kelvin temperatures, and demonstrate that the nanodiamond remains confined within the trap even under high-intensity 1560 nm laser illumination. We would be happy to make available more details upon request.
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Submitted 20 August, 2025;
originally announced August 2025.
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Strong Confinement of a Nanodiamond in a Needle Paul Trap: Towards Matter-Wave Interferometry with Massive Objects
Authors:
Peter Skakunenko,
Daniel Folman,
Yaniv Bar-Haim,
Ron Folman
Abstract:
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle, can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in completely new regimes, as well as the interface between QM and GR, e.g., testing the quantization…
▽ More
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle, can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in completely new regimes, as well as the interface between QM and GR, e.g., testing the quantization of gravity. Consequently, there exists an intensive effort to realize such an interferometer. While several paths are being pursued, we focus on utilizing nanodiamonds as our particle, and a spin embedded in the nanodiamond together with Stern-Gerlach forces, to achieve a closed loop in space-time. There is a growing community of groups pursuing this path [1]. We are posting this technical note (as part of a series of seven such notes), to highlight our plans and solutions concerning various challenges in this ambitious endeavor, hoping this will support this growing community. In this work, we achieve strong confinement of a levitated particle, which is crucial for angular confinement, precise positioning, and perhaps also advantageous for deep cooling. We designed a needle Paul trap with a controllable distance between the electrodes, giving rise to a strong electric gradient. By combining it with an effective charging method - electrospray - we reach a trap frequency of up to 40 kHz, which is more than twice the state of the art. We believe that the designed trap could become a significant tool in the hands of the community working towards massive matter-wave interferometry. We would be happy to make more details available upon request.
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Submitted 11 November, 2025; v1 submitted 19 August, 2025;
originally announced August 2025.
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Fabrication of nano-diamonds with a single NV center: Towards matter-wave interferometry with massive objects
Authors:
Menachem Givon,
Yaniv Bar-Haim,
David Groswasser,
Asi Solodar,
Nadav Aharon,
Michael Belman,
Amit Yosefi,
Erez Golan,
Jurgen Jopp,
Ron Folman
Abstract:
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in previously unexplored regimes. It also opens the possibility of probing the interface between QM and…
▽ More
Quantum mechanics (QM) and General relativity (GR), also known as the theory of gravity, are the two pillars of modern physics. A matter-wave interferometer with a massive particle can test numerous fundamental ideas, including the spatial superposition principle - a foundational concept in QM - in previously unexplored regimes. It also opens the possibility of probing the interface between QM and GR, such as testing the quantization of gravity. Consequently, there exists an intensive effort to realize such an interferometer. While several approaches are being explored, we focus on utilizing nanodiamonds with embedded spins as test particles which, in combination with Stern-Gerlach forces, enable the realization of a closed-loop matter-wave interferometer in space-time. There is a growing community of groups pursuing this path [1]. We are posting this technical note (as part of a series of seven such notes), to highlight our plans and solutions concerning various challenges in this ambitious endeavor, hoping this will support this growing community. Here we discuss the design considerations for a high-precision enhanced-coherence nanodiamond source, review the fabrication processes used to produce nanodiamond pillars measuring 40 x 65 x 80 nm, summarize the characterization work completed to date, and conclude with an outlook on the remaining steps needed to finalize the source fabrication. We would be happy to make available more details upon request.
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Submitted 19 August, 2025;
originally announced August 2025.
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Reply to comment on: Observation of the quantum equivalence principle for matter-waves
Authors:
Or Dobkowski,
Barak Trok,
Peter Skakunenko,
Yonathan Japha,
David Groswasser,
Maxim Efremov,
Chiara Marletto,
Ivette Fuentes,
Roger Penrose,
Vlatko Vedral,
Wolfgang P. Schleich,
Ron Folman
Abstract:
We show that in contrast to a recent claim, the Quantum Galileo Interferometer is sensitive to a uniform gravitational field in the presence and even in the absence of the levitation condition.
We show that in contrast to a recent claim, the Quantum Galileo Interferometer is sensitive to a uniform gravitational field in the presence and even in the absence of the levitation condition.
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Submitted 30 April, 2025;
originally announced April 2025.
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Observation of quantum free fall and the consistency with the equivalence principle
Authors:
Or Dobkowski,
Barak Trok,
Peter Skakunenko,
Yonathan Japha,
David Groswasser,
Maxim Efremov,
Chiara Marletto,
Ivette Fuentes,
Roger Penrose,
Vlatko Vedral,
Wolfgang P. Schleich,
Ron Folman
Abstract:
The unification of quantum theory and the general theory of relativity - describing gravity, is one of the most important challenges in science. Einstein's general theory of relativity is based on the principle of equivalence, and has been confirmed to great accuracy for large bodies. However, in the quantum domain the equivalence principle has been predicted to take a unique form involving a gaug…
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The unification of quantum theory and the general theory of relativity - describing gravity, is one of the most important challenges in science. Einstein's general theory of relativity is based on the principle of equivalence, and has been confirmed to great accuracy for large bodies. However, in the quantum domain the equivalence principle has been predicted to take a unique form involving a gauge phase, equal to the quantum phase of a free-falling object. To measure this phase, we realize a novel cold-atom interferometer in which one wave-packet stays static in the laboratory frame while the other is in free fall. The observed relative-phase of the wave-packets confirms the predicted phase of a free-falling object, and shows that in our low energy regime, the equivalence principle may be applied to the quantum domain. Our observation constitutes a fundamental test of the interface between quantum theory and gravity. The new interferometer also opens the door for further probing of the latter interface, as well as to searches for new physics.
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Submitted 7 December, 2025; v1 submitted 20 February, 2025;
originally announced February 2025.
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A Multi-Messenger Search for Exotic Field Emission with a Global Magnetometer Network
Authors:
Sami S. Khamis,
Ibrahim A. Sulai,
Paul Hamilton,
S. Afach,
B. C. Buchler,
D. Budker,
N. L. Figueroa,
R. Folman,
D. Gavilán-Martín,
M. Givon,
Z. D. Grujić,
H. Guo,
M. P. Hedges,
D. F. Jackson Kimball,
D. Kim,
E. Klinger,
T. Kornack,
A. Kryemadhi,
N. Kukowski,
G. Lukasiewicz,
H. Masia-Roig,
M. Padniuk,
C. A. Palm,
S. Y. Park,
X. Peng
, et al. (16 additional authors not shown)
Abstract:
Quantum sensor networks in combination with traditional astronomical observations are emerging as a novel modality for multi-messenger astronomy. Here we develop a generic analysis framework that uses a data-driven approach to model the sensitivity of a quantum sensor network to astrophysical signals as a consequence of beyond-the-Standard Model (BSM) physics. The analysis method evaluates correla…
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Quantum sensor networks in combination with traditional astronomical observations are emerging as a novel modality for multi-messenger astronomy. Here we develop a generic analysis framework that uses a data-driven approach to model the sensitivity of a quantum sensor network to astrophysical signals as a consequence of beyond-the-Standard Model (BSM) physics. The analysis method evaluates correlations between sensors to search for BSM signals coincident with astrophysical triggers such as black hole mergers, supernovae, or fast radio bursts. Complementary to astroparticle approaches that search for particlelike signals (e.g. WIMPs), quantum sensors are sensitive to wavelike signals from exotic quantum fields. This analysis method can be applied to networks of different types of quantum sensors, such as atomic clocks, matter-wave interferometers, and nuclear clocks, which can probe many types of interactions between BSM fields and standard model particles.
We use this analysis method to carry out the first direct search utilizing a terrestrial network of precision quantum sensors for BSM fields emitted during a black hole merger. Specifically we use the Global Network of Optical Magnetometers for Exotic physics (GNOME) to perform a search for exotic low-mass field (ELF) bursts generated in coincidence with a gravitational wave signal from a binary black hole merger (GW200311 115853) detected by LIGO/Virgo on the 11th of March 2020. The associated gravitational wave heralds the arrival of the ELF burst that interacts with the spins of fermions in the magnetometers. This enables GNOME to serve as a tool for multi-messenger astronomy. Our search found no significant events, and consequently we place the first lab-based limits on combinations of ELF production and coupling parameters.
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Submitted 20 May, 2025; v1 submitted 18 July, 2024;
originally announced July 2024.
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Chip-Scale Point-Source Sagnac Interferometer by Phase-Space Squeezing
Authors:
Yiftach Halevy,
Yali Cina,
Omer Feldman,
David Groswasser,
Yonathan Japha,
Ron Folman
Abstract:
Matter-wave interferometry plays a significant role in scientific research and technological applications. While position-momentum phase-space squeezing has been demonstrated to increase the coherence of atom sources by reducing momentum spread, we theoretically investigate the potential advantages of the opposite squeezing. As a case study, we analytically and numerically examine its effect on po…
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Matter-wave interferometry plays a significant role in scientific research and technological applications. While position-momentum phase-space squeezing has been demonstrated to increase the coherence of atom sources by reducing momentum spread, we theoretically investigate the potential advantages of the opposite squeezing. As a case study, we analytically and numerically examine its effect on point source atom interferometry (PSI) for rotation sensing. Our analysis reveals that this squeezed PSI (SPSI) approach can significantly improve sensitivity and dynamic range while enabling shorter cycle times and higher repetition rates. Through simulations, we identify parameter spaces where sensitivity and dynamic range are enhanced by orders of magnitude. Under a specific definition of compactness, our calculations show that SPSI outperforms standard PSI by over four orders of magnitude. These theoretical findings suggest that SPSI could either enhance performance in standard-sized devices or maintain performance in miniaturized chip-scale devices, potentially paving the way for new practical applications.
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Submitted 15 October, 2025; v1 submitted 27 May, 2024;
originally announced May 2024.
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Heading Error Compensation in a Portable Optical Magnetometer Using a Double-Pass Single Beam Configuration
Authors:
Yossi Rosenzweig,
Dmitriy Tokar,
Igor Shcerback,
Menachem Givon,
Ron Folman
Abstract:
Optically pumped magnetometers are ultra-sensitive devices, but this sensitivity can significantly degrade due to heading errors, whereby a change in the angle between the pumping laser and the magnetic field translates to a change in the magnetic field readout. We present a portable all-optical single-beam magnetometer with a reduced heading error due to a double-pass configuration. We analyze it…
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Optically pumped magnetometers are ultra-sensitive devices, but this sensitivity can significantly degrade due to heading errors, whereby a change in the angle between the pumping laser and the magnetic field translates to a change in the magnetic field readout. We present a portable all-optical single-beam magnetometer with a reduced heading error due to a double-pass configuration. We analyze it both theoretically and experimentally. In addition to this significant improvement in performance, the increased interaction length of the laser with the cell enhances the signal. Overall, the new configuration enables better accuracy, as well as the reduction of the cell temperature, laser power, and further miniaturization of the sensing head. This work opens the door for a simple and robust sub-pT portable sensor in Earth field.
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Submitted 4 August, 2023; v1 submitted 26 July, 2023;
originally announced July 2023.
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Limit on spatial quantum superpositions with massive objects due to phonons
Authors:
Carsten Henkel,
Ron Folman
Abstract:
It has been a long-standing goal to bring massive objects into a superposition of different locations in real space, not only to confirm quantum theory in new regimes, but also to explore the interface with gravity. The main challenge is usually thought to arise from forces or scattering due to environmental fields and particles that decohere the large object's wave function into a statistical mix…
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It has been a long-standing goal to bring massive objects into a superposition of different locations in real space, not only to confirm quantum theory in new regimes, but also to explore the interface with gravity. The main challenge is usually thought to arise from forces or scattering due to environmental fields and particles that decohere the large object's wave function into a statistical mixture. We unveil a decoherence channel which cannot be eliminated by improved isolation from the environment. It originates from sound waves within the object, which are excited as part of any splitting process and carry partial "Welcher Weg" information. This puts stringent constraints on future spatial superpositions of large objects.
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Submitted 27 September, 2024; v1 submitted 24 May, 2023;
originally announced May 2023.
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What can a GNOME do? Search targets for the Global Network of Optical Magnetometers for Exotic physics searches
Authors:
S. Afach,
D. Aybas Tumturk,
H. Bekker,
B. C. Buchler,
D. Budker,
K. Cervantes,
A. Derevianko,
J. Eby,
N. L. Figueroa,
R. Folman,
D. Gavil'an Martin,
M. Givon,
Z. D. Grujic,
H. Guo,
P. Hamilton,
M. P. Hedges,
D. F. Jackson Kimball,
S. Khamis,
D. Kim,
E. Klinger,
A. Kryemadhi,
X. Liu,
G. Lukasiewicz,
H. Masia-Roig,
M. Padniuk
, et al. (28 additional authors not shown)
Abstract:
Numerous observations suggest that there exist undiscovered beyond-the-Standard-Model particles and fields. Because of their unknown nature, these exotic particles and fields could interact with Standard Model particles in many different ways and assume a variety of possible configurations. Here we present an overview of the Global Network of Optical Magnetometers for Exotic physics searches (GNOM…
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Numerous observations suggest that there exist undiscovered beyond-the-Standard-Model particles and fields. Because of their unknown nature, these exotic particles and fields could interact with Standard Model particles in many different ways and assume a variety of possible configurations. Here we present an overview of the Global Network of Optical Magnetometers for Exotic physics searches (GNOME), our ongoing experimental program designed to test a wide range of exotic physics scenarios. The GNOME experiment utilizes a worldwide network of shielded atomic magnetometers (and, more recently, comagnetometers) to search for spatially and temporally correlated signals due to torques on atomic spins from exotic fields of astrophysical origin. We survey the temporal characteristics of a variety of possible signals currently under investigation such as those from topological defect dark matter (axion-like particle domain walls), axion-like particle stars, solitons of complex-valued scalar fields (Q-balls), stochastic fluctuations of bosonic dark matter fields, a solar axion-like particle halo, and bursts of ultralight bosonic fields produced by cataclysmic astrophysical events such as binary black hole mergers.
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Submitted 4 May, 2023; v1 submitted 2 May, 2023;
originally announced May 2023.
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In-vacuum microwave resonator for a compact cold atom frequency standard
Authors:
M. Givon,
L. Habib,
A. Waxman,
Y. Bar-Haim,
O. Amit,
Y. Cina,
G. Boneh,
D. Groswasser,
T. David,
B. Levy,
A. Stern,
R. Folman
Abstract:
A physics package for a compact cold atomic clock is hereby presented. The uniqueness of this package is its small dimensions that enable, for the first time, implementation of a primary cold atomic clock in a standard package of 3U height (=133mm). These dimensions are made possible by using an in-vacuum Microwave (MW) Loop Gap Resonator (LGR) whose length and diameter can be reduced from those o…
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A physics package for a compact cold atomic clock is hereby presented. The uniqueness of this package is its small dimensions that enable, for the first time, implementation of a primary cold atomic clock in a standard package of 3U height (=133mm). These dimensions are made possible by using an in-vacuum Microwave (MW) Loop Gap Resonator (LGR) whose length and diameter can be reduced from those of a typical resonator. Following our presentation of the design, we analyze the homogeneity of the MW field amplitude and phase. We find that the expected clock instability due to non-uniformity of the MW field is $\sim1.5\cdot10^{-14}$/day. Adding other clock errors, we estimate the total uncertainty of a cold atomic clock of this design will be around $\sim2\cdot10^{-14}$/day which results in a time drift of a few nanoseconds/day. Such a clock can serve as a primary-grade frequency reference, and may replace the cesium beam atomic clock and the GPS-disciplined rubidium atomic clocks.
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Submitted 18 August, 2022;
originally announced August 2022.
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Multi-pass guided atomic Sagnac interferometer for high-performance rotation sensing
Authors:
Samuel Moukouri,
Yonathan Japha,
Mark Keil,
Tal David,
David Groswasser,
Menachem Givon,
Ron Folman
Abstract:
Matter-wave interferometry with atoms propagating in a guiding potential is expected to provide compact, scalable and precise inertial sensing. However, a rotation sensing device based on the Sagnac effect with atoms guided in a ring has not yet been implemented despite continuous efforts during the last two decades. Here we discuss some intrinsic effects that limit the coherence in such a device…
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Matter-wave interferometry with atoms propagating in a guiding potential is expected to provide compact, scalable and precise inertial sensing. However, a rotation sensing device based on the Sagnac effect with atoms guided in a ring has not yet been implemented despite continuous efforts during the last two decades. Here we discuss some intrinsic effects that limit the coherence in such a device and propose a scheme that overcomes these limitations and enables a multi-pass guiding Sagnac interferometer with a Bose-Einstein condensate (BEC) on a chip in a ring potential. We analyze crucial dephasing effects: potential roughness, phase diffusion due to atom-atom interactions and number uncertainty, and phase fluctuations. Owing to the recent progress in achieving high momentum beam splitting, creating smooth guides, and manipulating the matter-wavepacket propagation, guided interferometry can be implemented within the coherence time allowed by phase diffusion. Despite the lower particle flux in a guided Sagnac ring and the miniaturization of the interferometer, the estimated sensitivity, for reasonable and practical realizations of an atom chip-based gyroscope, is comparable to that of free-space interferometers, reaching 45 nrads^{-1}Hz^{-1/2}. A significant improvement over state-of-the-art free-space gyrocope sensitivities can be envisioned by using thermal atoms instead of a BEC, whereby the interferometer can be operated in a continuous fashion with the coherence limited by the scattering rate of the atoms with the background gas. Taking into account the sensitivity times length of the interferometer as the figure of merit which takes into account compactness, our configuration is expected to deliver a potential improvement of 2-4 orders of magnitude over state-of-the-art free-space gyroscopes for a BEC, and 4-6 orders of magnitude for thermal atoms.
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Submitted 22 July, 2021; v1 submitted 7 July, 2021;
originally announced July 2021.
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Realization of a complete Stern-Gerlach interferometer: Towards a test of quantum gravity
Authors:
Yair Margalit,
Or Dobkowski,
Zhifan Zhou,
Omer Amit,
Yonathan Japha,
Samuel Moukouri,
Daniel Rohrlich,
Anupam Mazumdar,
Sougato Bose,
Carsten Henkel,
Ron Folman
Abstract:
The Stern-Gerlach effect, discovered a century ago, has become a paradigm of quantum mechanics. Surprisingly there has been little evidence that the original scheme with freely propagating atoms exposed to gradients from macroscopic magnets is a fully coherent quantum process. Specifically, no full-loop Stern-Gerlach interferometer has been realized with the scheme as envisioned decades ago. Furth…
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The Stern-Gerlach effect, discovered a century ago, has become a paradigm of quantum mechanics. Surprisingly there has been little evidence that the original scheme with freely propagating atoms exposed to gradients from macroscopic magnets is a fully coherent quantum process. Specifically, no full-loop Stern-Gerlach interferometer has been realized with the scheme as envisioned decades ago. Furthermore, several theoretical studies have explained why such an interferometer is a formidable challenge. Here we provide a detailed account of the first full-loop Stern-Gerlach interferometer realization, based on highly accurate magnetic fields, originating from an atom chip, that ensure coherent operation within strict constraints described by previous theoretical analyses. Achieving this high level of control over magnetic gradients is expected to facilitate technological as well as fundamental applications, such as probing the interface of quantum mechanics and gravity. While the experimental realization described here is for a single atom, future challenges would benefit from utilizing macroscopic objects doped with a single spin. Specifically, we show that such an experiment is in principle feasible, opening the door to a new era of fundamental probes.
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Submitted 21 November, 2020;
originally announced November 2020.
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Stern-Gerlach Interferometry with the Atom Chip
Authors:
Mark Keil,
Shimon Machluf,
Yair Margalit,
Zhifan Zhou,
Omer Amit,
Or Dobkowski,
Yonathan Japha,
Samuel Moukouri,
Daniel Rohrlich,
Zina Binstock,
Yaniv Bar-Haim,
Menachem Givon,
David Groswasser,
Yigal Meir,
Ron Folman
Abstract:
In this invited review in honor of 100 years since the Stern-Gerlach (SG) experiments, we describe a decade of SG interferometry on the atom chip. The SG effect has been a paradigm of quantum mechanics throughout the last century, but there has been surprisingly little evidence that the original scheme, with freely propagating atoms exposed to gradients from macroscopic magnets, is a fully coheren…
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In this invited review in honor of 100 years since the Stern-Gerlach (SG) experiments, we describe a decade of SG interferometry on the atom chip. The SG effect has been a paradigm of quantum mechanics throughout the last century, but there has been surprisingly little evidence that the original scheme, with freely propagating atoms exposed to gradients from macroscopic magnets, is a fully coherent quantum process. Specifically, no full-loop SG interferometer (SGI) has been realized with the scheme as envisioned decades ago. Furthermore, several theoretical studies have explained why it is a formidable challenge. Here we provide a review of our SG experiments over the last decade. We describe several novel configurations such as that giving rise to the first SG spatial interference fringes, and the first full-loop SGI realization. These devices are based on highly accurate magnetic fields, originating from an atom chip, that ensure coherent operation within strict constraints described by previous theoretical analyses. Achieving this high level of control over magnetic gradients is expected to facilitate technological applications such as probing of surfaces and currents, as well as metrology. Fundamental applications include the probing of the foundations of quantum theory, gravity, and the interface of quantum mechanics and gravity. We end with an outlook describing possible future experiments.
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Submitted 6 November, 2020; v1 submitted 17 September, 2020;
originally announced September 2020.
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T^3-Stern-Gerlach Matter-Wave Interferometer
Authors:
O. Amit,
Y. Margalit,
O. Dobkowski,
Z. Zhou,
Y. Japha,
M. Zimmermann,
M. A. Efremov,
F. A. Narducci,
E. M. Rasel,
W. P. Schleich,
R. Folman
Abstract:
We present a unique matter-wave interferometer whose phase scales with the cube of the time the atom spends in the interferometer. Our scheme is based on a full-loop Stern-Gerlach interferometer incorporating four magnetic field gradient pulses to create a state-dependent force. In contrast to typical atom interferometers which make use of laser light for the splitting and recombination of the wav…
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We present a unique matter-wave interferometer whose phase scales with the cube of the time the atom spends in the interferometer. Our scheme is based on a full-loop Stern-Gerlach interferometer incorporating four magnetic field gradient pulses to create a state-dependent force. In contrast to typical atom interferometers which make use of laser light for the splitting and recombination of the wave packets, this realization uses no light and can therefore serve as a high-precision surface probe at very close distances.
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Submitted 11 August, 2019;
originally announced August 2019.
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Stern-Gerlach splitting of low-energy ion beams
Authors:
Carsten Henkel,
Georg Jacob,
Felix Stopp,
Ferdinand Schmidt-Kaler,
Mark Keil,
Yonathan Japha,
Ron Folman
Abstract:
We present a feasibility study with several magnetic field configurations for creating spin-dependent forces that can split a low-energy ion beam by the Stern-Gerlach effect. To the best of our knowledge, coherent spin-splittings of charged particles have yet to be realised. Our proposal is based on ion source parameters taken from a recent experiment that demonstrated single-ion implantation from…
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We present a feasibility study with several magnetic field configurations for creating spin-dependent forces that can split a low-energy ion beam by the Stern-Gerlach effect. To the best of our knowledge, coherent spin-splittings of charged particles have yet to be realised. Our proposal is based on ion source parameters taken from a recent experiment that demonstrated single-ion implantation from a high-brightness ion source combined with a radio-frequency Paul trap. The inhomogeneous magnetic fields can be created by permanently magnetised microstructures or from current-carrying wires with sizes in the micron range, such as those recently used in a successful implementation of the Stern-Gerlach effect with neutral atoms. All relevant forces (Lorentz force and image charges) are taken into account, and measurable splittings are found by analytical and numerical calculations.
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Submitted 10 April, 2019; v1 submitted 10 March, 2019;
originally announced March 2019.
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Survival of the fittest in the coherent evolution of quantum ensembles
Authors:
G. Liu,
O. Be'er,
Y. Margalit,
M. Givon,
D. Groswasser,
Y. Japha,
R. Folman
Abstract:
We report two novel effects in an inhomogeneous ensemble of two-level systems driven by an external field. First, we observe a rigidity of the oscillation frequency: the dominant Rabi oscillation frequency does not change with the frequency of the driving field, in contrast to the well-known law of Rabi frequency increase with growing detuning of the driving field. Second, we observe a time-depend…
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We report two novel effects in an inhomogeneous ensemble of two-level systems driven by an external field. First, we observe a rigidity of the oscillation frequency: the dominant Rabi oscillation frequency does not change with the frequency of the driving field, in contrast to the well-known law of Rabi frequency increase with growing detuning of the driving field. Second, we observe a time-dependent frequency shift of the ensemble-averaged oscillation. We show that these effects follow from the inhomogeneity of the two-level splitting across the ensemble, allowing for a distribution of local oscillations in which those with high frequencies interfere destructively and decay faster than those with a low frequency, which are the only to survive in the output signal. Hence, coherence emerges from long-lived oscillations in an inhomogeneous ensemble. We analyze the Fourier spectrum of the time-dependent oscillation signal and find a non-trivial spectral structure that is double peaked for certain parameters. We show that the effects observed in alkali vapor are universal and expected in any system with a moderate inhomogeneity driven by an external field.
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Submitted 24 July, 2018; v1 submitted 2 March, 2018;
originally announced March 2018.
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Realization of a complete Stern-Gerlach interferometer
Authors:
Yair Margalit,
Zhifan Zhou,
Or Dobkowski,
Yonathan Japha,
Daniel Rohrlich,
Samuel Moukouri,
Ron Folman
Abstract:
The Stern-Gerlach (SG) effect, discovered almost a century ago, has become a paradigm of quantum mechanics. Surprisingly there is little evidence that the original scheme with freely propagating atoms exposed to gradients from macroscopic magnets is a fully coherent quantum process. Specifically, no high-visibility spatial interference pattern has been observed with such a scheme, and furthermore…
▽ More
The Stern-Gerlach (SG) effect, discovered almost a century ago, has become a paradigm of quantum mechanics. Surprisingly there is little evidence that the original scheme with freely propagating atoms exposed to gradients from macroscopic magnets is a fully coherent quantum process. Specifically, no high-visibility spatial interference pattern has been observed with such a scheme, and furthermore no full-loop SG interferometer has been realized with the scheme as envisioned decades ago. On the contrary, numerous theoretical studies explained why it is a near impossible endeavor. Here we demonstrate for the first time both a high-visibility spatial SG interference pattern and a full-loop SG interferometer, based on an accurate magnetic field, originating from an atom chip, that ensures coherent operation within strict constraints described by previous theoretical analyses. This also allows us to observe the gradual emergence of time-irreversibility as the splitting is increased. Finally, achieving this high level of control over magnetic gradients may facilitate technological applications such as large-momentum-transfer beam splitting for metrology with atom interferometry, ultra-sensitive probing of electron transport down to shot-noise and squeezed currents, as well as nuclear magnetic resonance and compact accelerators.
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Submitted 27 February, 2018; v1 submitted 8 January, 2018;
originally announced January 2018.
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Fifteen Years of Cold Matter on the Atom Chip: Promise, Realizations, and Prospects
Authors:
Mark Keil,
Omer Amit,
Shuyu Zhou,
David Groswasser,
Yonathan Japha,
Ron Folman
Abstract:
Here we review the field of atom chips in the context of Bose-Einstein Condensates (BEC) as well as cold matter in general. Twenty years after the first realization of the BEC and fifteen years after the realization of the atom chip, the latter has been found to enable extraordinary feats: from producing BECs at a rate of several per second, through the realization of matter-wave interferometry, a…
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Here we review the field of atom chips in the context of Bose-Einstein Condensates (BEC) as well as cold matter in general. Twenty years after the first realization of the BEC and fifteen years after the realization of the atom chip, the latter has been found to enable extraordinary feats: from producing BECs at a rate of several per second, through the realization of matter-wave interferometry, and all the way to novel probing of surfaces and new forces. In addition, technological applications are also being intensively pursued. This review will describe these developments and more, including new ideas which have not yet been realized.
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Submitted 16 May, 2016;
originally announced May 2016.
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Investigation of two-frequency Paul traps for antihydrogen production
Authors:
Nathan Leefer,
Kai Krimmel,
William Bertsche,
Dmitry Budker,
Joel Fajans,
Ron Folman,
Hartmut Haeffner,
Ferdinand Schmidt-Kaler
Abstract:
Radio-frequency (rf) Paul traps operated with multifrequency rf trapping potentials provide the ability to independently confine charged particle species with widely different charge-to-mass ratios. In particular, these traps may find use in the field of antihydrogen recombination, allowing antiproton and positron clouds to be trapped and confined in the same volume without the use of large superc…
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Radio-frequency (rf) Paul traps operated with multifrequency rf trapping potentials provide the ability to independently confine charged particle species with widely different charge-to-mass ratios. In particular, these traps may find use in the field of antihydrogen recombination, allowing antiproton and positron clouds to be trapped and confined in the same volume without the use of large superconducting magnets. We explore the stability regions of two-frequency Paul traps and perform numerical simulations of small, multispecies charged-particle mixtures that indicate the promise of these traps for antihydrogen recombination.
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Submitted 13 October, 2016; v1 submitted 30 March, 2016;
originally announced March 2016.
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Robust spatial coherence 5$\,μ$m from a room-temperature atom chip
Authors:
Shuyu Zhou,
David Groswasser,
Mark Keil,
Yonathan Japha,
Ron Folman
Abstract:
We study spatial coherence near a classical environment by loading a Bose-Einstein condensate into a magnetic lattice potential and observing diffraction. Even very close to a surface (5$\,μ$m), and even when the surface is at room temperature, spatial coherence persists for a relatively long time ($\ge$500$\,$ms). In addition, the observed spatial coherence extends over several lattice sites, a s…
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We study spatial coherence near a classical environment by loading a Bose-Einstein condensate into a magnetic lattice potential and observing diffraction. Even very close to a surface (5$\,μ$m), and even when the surface is at room temperature, spatial coherence persists for a relatively long time ($\ge$500$\,$ms). In addition, the observed spatial coherence extends over several lattice sites, a significantly greater distance than the atom-surface separation. This opens the door for atomic circuits, and may help elucidate the interplay between spatial dephasing, inter-atomic interactions, and external noise.
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Submitted 13 June, 2016; v1 submitted 11 May, 2015;
originally announced May 2015.
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Long spatial coherence times a few micro-meters from a room temperature surface
Authors:
Shuyu Zhou,
David Groswasser,
Mark Keil,
Yonathan Japha,
Ron Folman
Abstract:
The search for quantum coherence based on isolated atoms integrated with a room temperature solid state device (so-called atomchip [1-3]) has been intensifying in the last decade, with advances being made towards applications such as clocks, quantum information processing, surface probing and acceleration and gravitational field sensors. Such a device will also enable (and to some extent has alrea…
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The search for quantum coherence based on isolated atoms integrated with a room temperature solid state device (so-called atomchip [1-3]) has been intensifying in the last decade, with advances being made towards applications such as clocks, quantum information processing, surface probing and acceleration and gravitational field sensors. Such a device will also enable (and to some extent has already enabled) novel experiments in fundamental physics (e.g., [4-7]). Here we report on the trapping and maintenance of spatial coherence of atoms (in a Bose-Einstein Condensate -- BEC) about 5$μ$m from a room temperature surface, reducing significantly the distance previously achieved between the spatially coherent atoms and their classical environment [8-12], and most importantly entering the regime where atomic circuits are enabled. In addition, we enter the interesting regime in which the distance to the surface is much smaller than the probed coherence length, a regime in which the spatial dephasing reaches its maximal rate.
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Submitted 5 February, 2015;
originally announced February 2015.
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Microwave saturation spectroscopy of nitrogen-vacancy ensembles in diamond
Authors:
P. Kehayias,
M. Mrózek,
V. M. Acosta,
A. Jarmola,
D. S. Rudnicki,
R. Folman,
W. Gawlik,
D. Budker
Abstract:
Negatively-charged nitrogen-vacancy (NV$^-$) centers in diamond have generated much recent interest for their use in sensing. The sensitivity improves when the NV ground-state microwave transitions are narrow, but these transitions suffer from inhomogeneous broadening, especially in high-density NV ensembles. To better understand and remove the sources of broadening, we demonstrate room-temperatur…
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Negatively-charged nitrogen-vacancy (NV$^-$) centers in diamond have generated much recent interest for their use in sensing. The sensitivity improves when the NV ground-state microwave transitions are narrow, but these transitions suffer from inhomogeneous broadening, especially in high-density NV ensembles. To better understand and remove the sources of broadening, we demonstrate room-temperature spectral "hole burning" of the NV ground-state transitions. We find that hole burning removes the broadening caused by magnetic fields from $^{13}$C nuclei and demonstrate that it can be used for magnetic-field-insensitive thermometry.
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Submitted 9 March, 2014;
originally announced March 2014.
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Magnetic-film atom chip with 10 $μ$m period lattices of microtraps for quantum information science with Rydberg atoms
Authors:
V. Y. F. Leung,
D. R. M. Pijn,
H. Schlatter,
L. Torralbo-Campo,
A. La Rooij,
G. B. Mulder,
J. Naber,
M. L. Soudijn,
A. Tauschinsky,
C. Abarbanel,
B. Hadad,
E. Golan,
R. Folman,
R. J. C. Spreeuw
Abstract:
We describe the fabrication and construction of a setup for creating lattices of magnetic microtraps for ultracold atoms on an atom chip. The lattice is defined by lithographic patterning of a permanent magnetic film. Patterned magnetic-film atom chips enable a large variety of trapping geometries over a wide range of length scales. We demonstrate an atom chip with a lattice constant of 10 $μ$m, s…
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We describe the fabrication and construction of a setup for creating lattices of magnetic microtraps for ultracold atoms on an atom chip. The lattice is defined by lithographic patterning of a permanent magnetic film. Patterned magnetic-film atom chips enable a large variety of trapping geometries over a wide range of length scales. We demonstrate an atom chip with a lattice constant of 10 $μ$m, suitable for experiments in quantum information science employing the interaction between atoms in highly-excited Rydberg energy levels. The active trapping region contains lattice regions with square and hexagonal symmetry, with the two regions joined at an interface. A structure of macroscopic wires, cut out of a silver foil, was mounted under the atom chip in order to load ultracold $^{87}$Rb atoms into the microtraps. We demonstrate loading of atoms into the square and hexagonal lattice sections simultaneously and show resolved imaging of individual lattice sites. Magnetic-film lattices on atom chips provide a versatile platform for experiments with ultracold atoms, in particular for quantum information science and quantum simulation.
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Submitted 1 July, 2014; v1 submitted 18 November, 2013;
originally announced November 2013.
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Diamond Magnetometry of Superconducting Thin Films
Authors:
A. Waxman,
H. Schlussel,
D. Groswasser,
V. M. Acosta,
L. -S. Bouchard,
D. Budker,
R. Folman
Abstract:
In recent years diamond magnetometers based on the nitrogen-vacancy (NV) center have been of considerable interest for magnetometry applications at the nanoscale. An interesting application which is well suited for NV centers is the study of nanoscale magnetic phenomena in superconducting materials. We employ the magnetic sensitivity of NV centers in diamond to interrogate the magnetic properties…
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In recent years diamond magnetometers based on the nitrogen-vacancy (NV) center have been of considerable interest for magnetometry applications at the nanoscale. An interesting application which is well suited for NV centers is the study of nanoscale magnetic phenomena in superconducting materials. We employ the magnetic sensitivity of NV centers in diamond to interrogate the magnetic properties of a thin-layer yttrium barium copper oxide (YBCO) superconductor. Using fluorescence-microscopy methods and samples integrated with an NV sensor on a microchip, we measure the temperature of phase transition in the layer to be 70.0(2) K, and the penetration field of vortices to be 46(4) G. We observe the pinning of the vortices in the layer at 65 K, and estimate their density after cooling the sample in a ~ 10 G field to be 0.45(1) μm^{-2}. These measurements are done with a 10 nm thick NV layer, so that high spatial resolution may be enabled in the future. Based on these results, we anticipate that this magnetometer could be useful for imaging the structure and dynamics of vortices. As an outlook, we present a fabrication method for a superconductor chip designed for this purpose.
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Submitted 5 February, 2014; v1 submitted 12 August, 2013;
originally announced August 2013.
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Magic frequencies in atom-light interaction for precision probing of the density matrix
Authors:
Menachem Givon,
Yair Margalit,
Amir Waxman,
Tal David,
David Groswasser,
Yonathan Japha,
Ron Folman
Abstract:
We analyze theoretically and experimentally the existence of a {\it magic frequency} for which the absorption of a linearly polarized light beam by vapor alkali atoms is independent of the population distribution among the Zeeman sub-levels and the angle between the beam and a magnetic field. The phenomenon originates from a peculiar cancelation of the contributions of higher moments of the atomic…
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We analyze theoretically and experimentally the existence of a {\it magic frequency} for which the absorption of a linearly polarized light beam by vapor alkali atoms is independent of the population distribution among the Zeeman sub-levels and the angle between the beam and a magnetic field. The phenomenon originates from a peculiar cancelation of the contributions of higher moments of the atomic density matrix, and is described using the Wigner-Eckart theorem and inherent properties of Clebsch-Gordan coefficients. One important application is the robust measurement of the hyperfine population.
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Submitted 5 June, 2013;
originally announced June 2013.
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High momentum splitting of matter-waves by an atom chip field gradient beam-splitter
Authors:
Shimon Machluf,
Yonathan Japha,
Ron Folman
Abstract:
The splitting of matter-waves into a superposition of spatially separated states is a fundamental tool for studying the basic tenets of quantum mechanics and other theories, as well as a building block for numerous technological applications. We report the realization of a matter-wave beam splitter based on magnetic field gradients on an atom chip, which can be used for freely propagating or trapp…
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The splitting of matter-waves into a superposition of spatially separated states is a fundamental tool for studying the basic tenets of quantum mechanics and other theories, as well as a building block for numerous technological applications. We report the realization of a matter-wave beam splitter based on magnetic field gradients on an atom chip, which can be used for freely propagating or trapped atoms in a Bose-Einstein condensate or a thermal state. It has a wide dynamic range of momentum transfer and operation time. Differential velocities exceeding 0.5 m/s can be achieved in a few micro-seconds. The beam splitter may enable a wide range of applications, such as, fundamental studies of many-body entanglement and dephasing processes, probing classical and quantum properties of nearby solids, and metrology of rotation, acceleration and gravity on a chip scale.
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Submitted 1 November, 2012; v1 submitted 13 August, 2012;
originally announced August 2012.
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On the possibility of a relativistic correction to the E and B fields around a current-carrying wire
Authors:
Ron Folman
Abstract:
It is well known that electric and magnetic fields may change when they are observed from different frames of reference. For example, the motion of a charged probe particle moving parallel to a current-carrying wire would be described by utilizing different electric or magnetic fields, depending on from which frame of reference the system is observed and described. To describe the situation in all…
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It is well known that electric and magnetic fields may change when they are observed from different frames of reference. For example, the motion of a charged probe particle moving parallel to a current-carrying wire would be described by utilizing different electric or magnetic fields, depending on from which frame of reference the system is observed and described. To describe the situation in all frames by utilizing the theory of relativity, one has to first describe the situation in one particular frame, and this choice in the case of a current-carrying wire is the topic of this paper. In this study I examine an alternative to the standard choice, and consider its theoretical and experimental validity. An outcome of the alternative approach is that in the rest frame of a wire, running a current introduces also an electric field by giving rise to a minute charge. Present day experimental sensitivities, specifically those of cold ions, may be able to differentiate between the observable signatures predicted by the different approaches.
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Submitted 12 June, 2012; v1 submitted 12 September, 2011;
originally announced September 2011.
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Coupling between internal spin dynamics and external degrees of freedom in the presence of colored noise
Authors:
S. Machluf,
J. Coslovsky,
P. G. Petrov,
Y. Japha,
R. Folman
Abstract:
We observe asymmetric transition rates between Zeeman levels (spin-flips) of magnetically trapped atoms. The asymmetry strongly depends on the spectral shape of an applied noise. This effect follows from the interplay between the internal states of the atoms and their external degrees of freedom, where different trapped levels experience different potentials. Such insight may prove useful for cont…
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We observe asymmetric transition rates between Zeeman levels (spin-flips) of magnetically trapped atoms. The asymmetry strongly depends on the spectral shape of an applied noise. This effect follows from the interplay between the internal states of the atoms and their external degrees of freedom, where different trapped levels experience different potentials. Such insight may prove useful for controlling atomic states by the introduction of noise, as well as provide a better understanding of the effect of noise on the coherent operation of quantum systems.
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Submitted 7 October, 2010; v1 submitted 25 February, 2010;
originally announced February 2010.