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Experimental Implementation of Short-Path Non-adiabatic Geometric Gates in a Superconducting Circuit
Authors:
Xin-Xin Yang,
Liang-Liang Guo,
Hai-Feng Zhang,
Lei Du,
Chi Zhang,
Hao-Ran Tao,
Yong Chen,
Peng Duan,
Zhi-Long Jia,
Wei-Cheng Kong,
Guo-Ping Guo
Abstract:
The non-adiabatic geometric quantum computation (NGQC) has attracted a lot of attention for noise-resilient quantum control. However, previous implementations of NGQC require long evolution paths that make them more vulnerable to incoherent errors than their dynamical counterparts.In this work, we experimentally realize a universal short-path non-adiabatic geometric gate set (SPNGQC) with a 2-time…
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The non-adiabatic geometric quantum computation (NGQC) has attracted a lot of attention for noise-resilient quantum control. However, previous implementations of NGQC require long evolution paths that make them more vulnerable to incoherent errors than their dynamical counterparts.In this work, we experimentally realize a universal short-path non-adiabatic geometric gate set (SPNGQC) with a 2-times shorter evolution path on a superconducting quantum processor. Characterizing with both quantum process tomography and randomized benchmarking methods, we report an average single-qubit gate fidelity of 99.86% and a two-qubit gate fidelity of 97.9%. Additionally, we demonstrate superior robustness of single-qubit SP-NGQC gate to Rabi frequency error in some certain parameter space by comparing their performance to those of the dynamical gates and the former NGQC gates.
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Submitted 22 March, 2023;
originally announced March 2023.
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Vector exceptional points with strong superchiral fields
Authors:
Tong Wu,
Weixuan Zhang,
Huizhen Zhang,
Saisai Hou,
Guangyuan Chen,
Ruibin Liu,
Cuicui Lu,
Jiafang Li,
Rongyao Wang,
Pengfei Duan,
Junjie Li,
Bo Wang,
Lei Shi,
Jian Zi,
Xiangdong Zhang
Abstract:
Exceptional points(EPs), branch points of complex energy surfaces at which eigenvalues and eigenvectors coalesce, are ubiquitous in non-Hermitian systems. Many novel properties and applications have been proposed around the EPs. One of the important applications is to enhance the detection sensitivity. However, due to the lack of single-handed superchiral fields, all of the proposed EP-based sensi…
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Exceptional points(EPs), branch points of complex energy surfaces at which eigenvalues and eigenvectors coalesce, are ubiquitous in non-Hermitian systems. Many novel properties and applications have been proposed around the EPs. One of the important applications is to enhance the detection sensitivity. However, due to the lack of single-handed superchiral fields, all of the proposed EP-based sensing mechanisms are only useful for the non-chiral discrimination. Here, we propose theoretically and demonstrate experimentally a new type of EP, which is a called radiation vector EP, to fulfill the homogeneous superchiral fields for chiral sensing. This type of EP is realized by suitably tuning the coupling strength and radiation losses for a pair of orthogonal polarization modes in the photonic crystal slab. Based on the unique modal-coupling property at the vector EP, we demonstrate that the uniform superchiral fields can be generated with two beams of lights illuminating on the photonic crystal slab from opposite directions. Thus, the designed photonic crystal slab, which supports the vector EP, can be used to perform surface-enhanced chiral detection. Our findings provide a new strategy for ultrasensitive characterization and quantification of molecular chirality, a key aspect for various bioscience and biomedicine applications.
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Submitted 27 February, 2020;
originally announced February 2020.
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A simultaneous feedback and feed-forward control and its application to realize a random walk on the Bloch sphere in a superconducting Xmon-qubit system
Authors:
Liang Xiang,
Zhiwen Zong,
Zhenhai Sun,
Ze Zhan,
Ying Fei,
Zhangjingzi Dong,
Chongxin Run,
Zhilong Jia,
Peng Duan,
Jianlan Wu,
Yi Yin,
Guoping Guo
Abstract:
Measurement-based feedback control is central in quantum computing and precise quantum control. Here we realize a fast and flexible field-programmable-gate-array-based feedback control in a superconducting Xmon qubit system. The latency of room-temperature electronics is custom optimized to be as short as 140 ns. Projective measurement of a signal qubit produces a feedback tag to actuate a conditi…
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Measurement-based feedback control is central in quantum computing and precise quantum control. Here we realize a fast and flexible field-programmable-gate-array-based feedback control in a superconducting Xmon qubit system. The latency of room-temperature electronics is custom optimized to be as short as 140 ns. Projective measurement of a signal qubit produces a feedback tag to actuate a conditional pulse gate to the qubit. In a feed-forward process, the measurement-based feedback tag is brought to a different target qubit for a conditional control. In a two-qubit experiment, the feedback and feed-forward controls are simultaneously actuated in consecutive steps. A quantum number is then generated by the signal qubit, and a random walk of the target qubit is correspondingly triggered and realized on the Bloch sphere. Our experiment provides a conceptually simple and intuitive benchmark for the feedback control in a multi-qubit system. The feedback system can be further scaled up for more complex feedback control experiments.
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Submitted 23 June, 2020; v1 submitted 22 September, 2019;
originally announced September 2019.
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Pressure-induced quantum phase transitions in topological insulator YbB6
Authors:
Yazhou Zhou,
Dae-Jeong Kim,
Priscila Ferrari Silveira Rosa,
Qi Wu,
Jing Guo,
Shang Zhang,
Zhe Wang,
Defen Kang,
Chao Zhang,
Wei Yi,
Yanchun Li,
Xiaodong Li,
Jing Liu,
Peiqian Duan,
Ming Zi,
Xiangjun Wei,
Zheng Jiang,
Yuying Huang,
Yi-feng Yang,
Zachary Fisk,
Liling Sun,
Zhongxian Zhao
Abstract:
Topological insulators (TIs) containing 4f electrons have recently attracted intensive interests due to the possible interplay of their non-trivial topological properties and strong electronic correlations. YbB6 and SmB6 are the prototypical systems with such unusual properties, which may be tuned by external pressure to give rise to new emergent phenomena. Here, we report the first observation, t…
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Topological insulators (TIs) containing 4f electrons have recently attracted intensive interests due to the possible interplay of their non-trivial topological properties and strong electronic correlations. YbB6 and SmB6 are the prototypical systems with such unusual properties, which may be tuned by external pressure to give rise to new emergent phenomena. Here, we report the first observation, through in-situ high pressure resistance, Hall, X-ray diffraction and X-ray absorption measurements, of two pressure-induced quantum phase transitions (QPTs) in YbB6. Our data revealthat the two insulating phases are separated by a metallic phase due to the pressure-driven valence change of Yb f-orbitals. In combination with previous studies, our results suggest that the two insulating states may be topologically different in nature and originate from the d-p and d-f hybridization, respectively. The tunable topological properties of YbB6 revealed in this study may shed light on the intriguing correlation between the topology and the 4f electrons from the perspective of pressure dependent studies.
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Submitted 22 June, 2015; v1 submitted 16 January, 2015;
originally announced January 2015.
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High temperature electronic behavior of La0.8Sr0.2MnO3 thin film
Authors:
Guotai Tan,
S. Dai,
P. Duan,
H. B. Lu,
K. Xie,
Y. L. Zhou,
Z. H. Chen
Abstract:
The electronic structure of La0.8Sr0..2MnO3/SrTiO thin film, which was prepared by Laser MBE, was studied by X-ray photoemission spectra (XPS) in the temperature interval of 300 to 1000 K. Experimental results showed that the electronic state of the thin film underwent a discontinuous variation between 350 K and 450 K, indicating that the metal-semiconductor transition was probably a discontinuo…
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The electronic structure of La0.8Sr0..2MnO3/SrTiO thin film, which was prepared by Laser MBE, was studied by X-ray photoemission spectra (XPS) in the temperature interval of 300 to 1000 K. Experimental results showed that the electronic state of the thin film underwent a discontinuous variation between 350 K and 450 K, indicating that the metal-semiconductor transition was probably a discontinuous phase transition. At high temperature (450 to 1000 K), both the binding energies of the atomic core level and valence-band of the film shifted up with increasing the temperature, while their line-widths became narrower, which were different from that observed at low temperature. These phenomena are attributed to the crystal lattice expansion and related Jahn-Teller distortion varying with temperature.
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Submitted 21 January, 2003;
originally announced January 2003.
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Structure, Magnetic Properties and Spin-glass Behavior in La$sub{0.9}Tesub{0.1}MnOsub{3}$
Authors:
Guotai Tan,
P. Duan,
S. Y. Dai,
Y. L. Zhou,
H. B. Lu,
Z. H. Chen
Abstract:
In this study we report the structure, magnetic and electrical transport properties of pervoskite oxide La$sub{0.9}Tesub{0.1}MnOsub{3}$. This is a novel material with the space group R-3c, which shows the spin-glass-like feature at low temperature and has a good colossal magnetoresistance behavior. The magnetoresistance ratio is about 51% at 200 K in a field of 4 T. The XPS measurement suggests…
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In this study we report the structure, magnetic and electrical transport properties of pervoskite oxide La$sub{0.9}Tesub{0.1}MnOsub{3}$. This is a novel material with the space group R-3c, which shows the spin-glass-like feature at low temperature and has a good colossal magnetoresistance behavior. The magnetoresistance ratio is about 51% at 200 K in a field of 4 T. The XPS measurement suggests that Te ions are in the Te$up{4+}$ state, while Mn ions may be in the 2+ and 3+ valence state.
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Submitted 21 January, 2003;
originally announced January 2003.
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Structure, electric and magnetic properties of the electron-doped manganese oxide: La{sub(1-x)}Te{sub(x)}MnO{sub(3)}(x=0.1, 0.15)
Authors:
Guotai Tan,
Shouyu Dai,
Ping Duan,
Huibin Lu,
Yueliang Zhou,
Zhenghao Chen
Abstract:
In this letter, the electrical and magnetic properties of La{sub(1-x)}Te{sub(x)}MnO{sub(3)}(x=0.1, 0.15), which is a new material and shows good colossal magnetoresistance (CMR) behavior, have been investigated. These compounds have rhombohedral structure. In this materical, Te replaced a part of La ions, which induced the lattice cell constriction and Mn-O-Mn bond angle widening. X-ray photoemi…
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In this letter, the electrical and magnetic properties of La{sub(1-x)}Te{sub(x)}MnO{sub(3)}(x=0.1, 0.15), which is a new material and shows good colossal magnetoresistance (CMR) behavior, have been investigated. These compounds have rhombohedral structure. In this materical, Te replaced a part of La ions, which induced the lattice cell constriction and Mn-O-Mn bond angle widening. X-ray photoemission spectroscopy (XPS) measurement revealed that the Te ions were in the tetravalent state and the manganese ions could be considered as in a mixture state of Mn{sup(2+)} and Mn{Sup(3+)}. Thus the material could be viewed as an electron-doped compound. The Curie temperature (Tc) was about 240 K and 255 K for x=0.1, 0.15, respectively. The maximum magnetoresistance ratio MR=[r(0)-r(H)]/r(0) was about 51% at 200 K and in the applied magnetic field of 40 kOe.
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Submitted 21 January, 2003; v1 submitted 28 October, 2002;
originally announced October 2002.