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Tight-binding photonics
Authors:
Jing Li,
Aodong Li,
Yutao Chen,
Tao Xiao,
Renwen Huang,
Xiaolu Zhuo,
Jun Guan,
Zhen Gao,
Peng Zhan,
Minghui Lu,
Biye Xie
Abstract:
Photonics, dealing with the generation, manipulation, and detection of photons in various systems, lays the foundation of many advanced technologies. A key task of photonics is to know how photons propagate in complex media such as periodic and aperiodic photonic crystals. The conventional wisdom is to numerically solve the Maxwell equations either by dedicated numerical techniques or brute-force…
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Photonics, dealing with the generation, manipulation, and detection of photons in various systems, lays the foundation of many advanced technologies. A key task of photonics is to know how photons propagate in complex media such as periodic and aperiodic photonic crystals. The conventional wisdom is to numerically solve the Maxwell equations either by dedicated numerical techniques or brute-force finite-element calculations. Recently, the strict analogy between photonic crystals and theoretical tight-binding models provides an unprecedentedly convenient wayof understanding the spectra and wavefunctions of photonic systems by mapping the complicated differential equationsinto matrixed Hamiltonians that can be easily solved through the band theory and exact diagonalization. in this paper, we present a timely review of tight-binding-like photonics in various platforms, covering fundamental theories, experimental realizations, unique physical efiects, and their potential applications. We also provide a brief outlook on the future trends of this active area. Our review offers an in-depth and comprehensive picture on this rapidly developing field and may shed light on the future design on advanced tight-binding-like photonic devices.
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Submitted 6 August, 2025;
originally announced August 2025.
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Unidirectional ultracompact DNA-templated optical antennas
Authors:
Fangjia Zhu,
Maria Sanz-Paz,
Antonio Fernandez-Dominguez,
Xiaolu Zhuo,
Luis M. Liz-Marzan,
Fernando D. Stefani,
Mauricio Pilo-Pais,
Guillermo P. Acuna
Abstract:
Optical nanoantennas are structures designed to manipulate light-matter interactions at the nanoscale by interfacing propagating light with localized optical fields. In recent years, a plethora of devices have been realized that are able to efficiently tailor the absorption and/or emission rates of fluorophores. By contrast, modifying the spatial characteristics of their radiation fields remains a…
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Optical nanoantennas are structures designed to manipulate light-matter interactions at the nanoscale by interfacing propagating light with localized optical fields. In recent years, a plethora of devices have been realized that are able to efficiently tailor the absorption and/or emission rates of fluorophores. By contrast, modifying the spatial characteristics of their radiation fields remains a challenge. Up to date, the designs providing directionality to fluorescence emission have required compound, complex geometries with overall dimensions comparable to the operating wavelength. Here, we present the fabrication and characterization of DNA-templated ultracompact optical antennas, with sub-wavelength sizes and capable of directing single-molecule fluorescence into predefined directions. Using the DNA origami methodology, two gold nanorods are assembled side-to-side with a separation gap of 5 nm. We show that a single fluorescent molecule placed at the tip of one of the nanorods drives the dimer antenna in anti-phase, leading to unidirectional emission.
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Submitted 7 April, 2022;
originally announced April 2022.
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Ultrafast photothermoelectric effect in Dirac semimetallic Cd3As2 revealed by terahertz emission
Authors:
Wei Lu,
Zipu Fan,
Yunkun Yang,
Junchao Ma,
Jiawei Lai,
Xiaoming Song,
Xiao Zhuo,
Zhaoran Xu,
Jing Liu,
Xiaodong Hu,
Shuyun Zhou,
Faxian Xiu,
Jinluo Cheng,
Dong Sun
Abstract:
The thermoelectric effects of topological semimetals have attracted tremendous research interest because many topological semimetals are excellent thermoelectric materials and thermoelectricity serves as one of their most important potential applications. In this work, we reveal the transient photothermoelectric response of Dirac semimetallic Cd3As2, namely the photo-Seebeck effect and photo-Nerns…
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The thermoelectric effects of topological semimetals have attracted tremendous research interest because many topological semimetals are excellent thermoelectric materials and thermoelectricity serves as one of their most important potential applications. In this work, we reveal the transient photothermoelectric response of Dirac semimetallic Cd3As2, namely the photo-Seebeck effect and photo-Nernst effect, by studying the terahertz (THz) emission from the transient photocurrent induced by these effects. Our excitation polarization and power dependence confirm that the observed THz emission is due to photothermoelectric effect instead of other nonlinear optical effect. Furthermore, when a weak magnetic field (~0.4 T) is applied, the response clearly indicates an order of magnitude enhancement on transient photothermoelectric current generation compared to the photo-Seebeck effect. Such enhancement supports an ambipolar transport nature of the photo-Nernst current generation in Cd3As2. These results highlight the enhancement of thermoelectric performance can be achieved in topological Dirac semimetals based on the Nernst effect, and our transient studies pave the way for thermoelectric devices applicable for high field circumstance when nonequilibrium state matters. The large THz emission due to highly efficient photothermoelectric conversion is comparable to conventional semiconductors through optical rectification and photo-Dember effect.
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Submitted 24 February, 2022;
originally announced February 2022.
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Ab-initio Mapping of Projected Local Density of States in Arbitrary Nanostructures: Application to Photonic Crystal Slabs and Cavities
Authors:
Gengyan Chen,
Yi-Cong Yu,
Xiao-Lu Zhuo,
Yong-Gang Huang,
Haoxiang Jiang,
Jing-Feng Liu,
Chong-Jun Jin,
Xue-Hua Wang
Abstract:
Based upon projected local density of states (PLDOS) for photons, we develop a local coupling theory to simultaneously treat the weak and strong interaction between a quantum emitter and photons in arbitrary nanostructures. The PLDOS is mapped by an extremely flexible and efficient method. The recent experiment observation for the photonic crystal slabs is very well interpreted by our ab-initio PL…
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Based upon projected local density of states (PLDOS) for photons, we develop a local coupling theory to simultaneously treat the weak and strong interaction between a quantum emitter and photons in arbitrary nanostructures. The PLDOS is mapped by an extremely flexible and efficient method. The recent experiment observation for the photonic crystal slabs is very well interpreted by our ab-initio PLDOS. More importantly, a bridge linking the PLDOS and cavity quantum electrodynamics is for the first time established to settle quality factor, g factor and vacuum Rabi splitting. Our work greatly enriches the knowledge about the interaction between light and matter in nanostructures.
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Submitted 27 October, 2012;
originally announced October 2012.