Article
Multidisciplinary Sciences
Jinqi Wu, Sanjib Ghosh, Yusong Gan, Ying Shi, Subhaskar Mandal, Handong Sun, Baile Zhang, Timothy C. H. Liew, Rui Su, Qihua Xiong
Summary: Unlike conventional lasers, topological lasers can emit coherent light in the presence of disorders and defects due to their nontrivial band topology. Exciton polariton topological lasers, which have the unique property of not requiring population inversion, are a promising platform for low-power consumption. In this study, we experimentally demonstrate the realization of topological corner states and achieve polariton corner state lasing with a low threshold at room temperature using a perovskite polariton system. This achievement opens up possibilities for on-chip active polaritonics using higher-order topology.
Article
Chemistry, Multidisciplinary
Sergey S. Kruk, Wenlong Gao, Duk-Yong Choi, Thomas Zentgraf, Shuang Zhang, Yuri Kivshar
Summary: Topological states of light localized at the boundaries of finite-size optical structures, originating from bulk properties, exhibit insensitivity to perturbations and enhance the robustness of photonic circuitries. The higher-order bulk-boundary correspondence relating higher-dimensional bulk states to lower-dimensional boundary states is of interest for miniaturization to the nanoscale. Nanoscale topological corner states in metasurfaces allow for enhanced light-matter interactions, potentially facilitating the miniaturization and integration of classical and quantum photonic devices on-chip.
Article
Physics, Multidisciplinary
Xiaoxiao Wu, Yan Meng, Yiran Hao, Ruo-Yang Zhang, Jensen Li, Xiang Zhang
Summary: A general scheme has been developed to induce topological corner modes (TCMs) in arbitrary geometries, allowing for construction and experimental observation of TCMs in square and pentagonal domains incompatible with underlying triangular lattices. This scheme enables arbitrary specification of numbers and positions of TCMs, which will be crucial for future on-chip topological circuits. The research findings reveal rich physics of aperiodic modulations and advance applications of TCMs in realistic scenarios.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Li Liang, Xiaoxi Zhou, Jun-Hui Hu, Hai-Xiao Wang, Jian-Hua Jiang, Bo Hou
Summary: Recent advancements in higher-order topology have opened up unprecedented opportunities for optical device designs and applications. In this study, a novel method to achieve rainbow trapping based on higher-order topological corner modes (HOTCMs) is proposed. The HOTCMs are constructed using breathing kagome photonic crystals with distinct topological phases. It is found that the HOTCMs localized at corners with different geometric configurations exhibit frequency dispersion, making them ideal for rainbow trapping. By designing a polygon structure containing multiple corner configurations, it is demonstrated that the HOTCMs can be excited with a frequency sequence locked to the corner order. The reported HOTCMs provide a new mechanism for achieving multi-frequency trapping and may have potential applications in integrated photonics.
Article
Engineering, Mechanical
Fang Hong, Kai Zhang, Liyuan Qi, Bin Ding, Zichen Deng
Summary: Higher-order topological insulators (HOTIs) have attracted attention for their topological properties of low-dimensional topological corner states and edge states. In this study, an elastic valley phononic crystal plate with an out-of-plane wide band gap is proposed to realize high-frequency edge states and corner states. The simulation and experimental results show that topologically protected edge waves can be transmitted to different locations and corner states still hold valley-selectivity in high-frequency bandgaps.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Optics
Shuai Shao, Li Liang, Jun-Hui Hu, Yin Poo, Hai-Xiao Wang
Summary: We study the band topologies in honeycomb-kagome photonic crystals (HKPCs) with first- and second-order pseudospin and valley degrees of freedom (DOFs). We observe the pseudospin-momentum locked edge states as the first-order topology and the multiple corner states as the second-order topology in hexagon-shaped supercells of HKPCs. Additionally, we discuss the effect of symmetry breaking on the pseudospin-momentum locked edge states.
Article
Physics, Applied
Jiangle He, Shiyin Jia, Yaxuan Li, Junzheng Hu, Renwen Huang, Guangxu Su, Minghui Lu, Peng Zhan, Fanxin Liu
Summary: In this work, we propose a theoretical scheme for achieving topologically switchable and valley-selective corner states based on two-dimensional C-3-symmetric photonic crystals. By concatenating two valley photonic crystals with contrasting topological indices, we demonstrate the emergence of two types of valley-locked chiral topological edge states resulting from valley-valley interaction. The system exhibits two distinct types of highly robust and localized corner states when the photonic crystals are spliced at a 60 degrees angle, but the corner states are absent when the splicing angle is set as 120 degrees.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Jia-Xiao Dai, Kai Wang, Shengyuan A. Yang, Y. X. Zhao
Summary: The article introduces a novel class of topological insulators, Takagi topological insulators (TTIs), protected by sublattice symmetry and PT symmetry, with classification space being unitary symmetric matrices. Particularly, global Takagi's factorization can be done in a 3D sphere and there exist corner zero modes with parity condition.
Article
Physics, Applied
Mingxing Li, Yueke Wang, Mengjia Lu, Tian Sang
Summary: This paper introduces a two-dimensional second-order topological photonic crystal based on a C-4 symmetric lattice, demonstrating a topological phase transition of the structure and the existence of edge and two types of corner states. The study enriches the understanding of corner states in photonic systems, distinguishing them based on robustness and mode area, and showing that the topological corner state can be embedded in bulk states, forming a bound state in continuum through simulation.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Optics
Meng-Cheng Jin, Yong-Feng Gao, Hao-Zhe Lin, Yi-Han He, Ming-Yang Chen
Summary: In this study, a configuration beyond the 2D SSH model is proposed for investigating topological corner states in photonic crystals. The configuration features a simple structure, direct formation of photonic band gaps, and strong robustness of corner states against defects.
Article
Engineering, Mechanical
Shuowei An, Tuo Liu, Haiyan Fan, He Gao, Zhongming Gu, Shanjun Liang, Sibo Huang, Yi Zheng, Yafeng Chen, Li Cheng, Jie Zhu
Summary: This study proposes a second-order elastic topological insulator (SETI) with valley-selective topological corner states, which can be activated by engineering the valley positions. Experimental results validate the existence of valley-selective corner states and the anti-symmetric displacement profile. This research provides a new approach for the flexible manipulation of elastic waves and has potential applications in various fields.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Optics
Yi-Han He, Yong-Feng Gao, Yue He, Xiao-Fei Qi, Jing-Qi Si, Ming Yang, Shu-Yang Zhou
Summary: In this paper, a two-dimensional all-dielectric PCs platform with kagome lattices is utilized to realize topological edge states in different frequency bands, and to achieve dual-band single channel waveguide and frequency divider. Furthermore, the origins of the two types of corner states in combined triangle and parallelogram box-shaped structures are investigated, enhancing the localized energy intensity in the PCs platform. These works have significant potential for application in integrated nanophotonic devices.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Kenichi Yatsugi, Shrinathan Esakimuthu Pandarakone, Hideo Iizuka
Summary: We experimentally demonstrate the existence of higher-order topological corner states in a breathing kagome lattice. The winding direction of each coil is engineered to hold C-3 symmetry in each triangle unit cell, allowing the emergence of higher-order topological corner states. Moreover, by tuning the distances between the coils, the topological and trivial phases can be switched. The observed corner states in the topological phase are confirmed through admittance measurements, and we illustrate the wireless power transfer between corner states, as well as between the bulk and corner states.
SCIENTIFIC REPORTS
(2023)
Article
Materials Science, Multidisciplinary
Yue He, Yong-Feng Gao, Ming Yang, Zhi-Guo Yan, Yi-Han He, Xiao-Fei Qi, Zi-Rui Liu
Summary: In this paper, we investigate the influence of Wannier center on topological edge states (TESs) and topological corner states (TCSs) in second-order topological photonic crystals (TPCs) with Kagome lattice. We propose a rhomboidal hybrid structure composed of topologically trivial and non-trivial PCs, which can achieve frequency division and beam splitting simultaneously. Additionally, we construct a parallelogram box-shaped structure of topologically non-trivial PCs with Kagome lattices and find that TCSs only appear in the close regions of acute-angled corners.
Article
Materials Science, Multidisciplinary
Nikita A. Olekhno, Alina D. Rozenblit, Valerii Kachin, Alexey A. Dmitriev, Oleg Burmistrov, Pavel S. Seregin, Dmitry Zhirihin, Maxim A. Gorlach
Summary: Topological corner states are zero-dimensional localized excitations protected by the bulk properties of the system, making them robust to disorder. In this study, we propose a D-4-symmetric system where the topological band gap is opened by additional long-range interactions that can be controlled in our resonant electrical circuit setup. Our experiments directly extract the topological invariant, demonstrating the topological origin of the observed symmetry-protected corner states.
Article
Materials Science, Multidisciplinary
Ming Lei, Sinisa Coh
Summary: In CrI3, an unusually large cross-polarized Raman signature of the A(g) phonon mode is observed, attributed to the combined effects of ferromagnetism on chromium atoms, spin-orbit interaction, and resonant effects. Surprisingly, the spin-orbit interaction potential is found to originate from iodine atoms, not chromium atoms where most of the magnetism lies. The Raman signature is analyzed with regards to magnetic order, magnetic moment direction, energy, light polarization, and carrier lifetime, revealing a strong phonon modulated magneto-optical Kerr effect in addition to the cross-polarized Raman signal.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Physics, Multidisciplinary
Thomas Schuster, Felix Flicker, Ming Li, Svetlana Kotochigova, Joel E. Moore, Jun Ye, Norman Y. Yao
Summary: The Hopf insulator is a weak topological insulator with conducting edge states protected by an integer-valued linking number invariant, which can be naturally realized in lattices of dipolar-interacting spins. The long-ranged, anisotropic nature of the dipole-dipole interactions allows for the precise detail required in the momentum-space structure, while different spin orientations ensure the necessary structure of the complex phases of the hoppings.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Tessa Cookmeyer, Johannes Motruk, Joel E. Moore
Summary: This study shows that under certain physical parameters, the additional four-spin interactions naturally generated in the Hubbard model will stabilize a chiral spin liquid of Kalmeyer-Laughlin type. By rewriting the interactions mean-field, a physical understanding of the origin of this spin liquid can be obtained.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Maxime Dupont, Nicholas E. Sherman, Joel E. Moore
Summary: Researchers have discovered anomalous spin transport at high temperatures challenges the traditional understanding of quantum behaviors in low temperatures, and through simulations, they have found a temperature-dependent connection between the two.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Vir B. Bulchandani, Manas Kulkarni, Joel E. Moore, Xiangyu Cao
Summary: In both quantum and classical Calogero models, the quasiparticle kinetic theory reduces to the free-streaming Boltzmann equation. A Bethe-Lax correspondence is developed in the classical case to reconcile the simple emergent behavior with the strongly interacting character of the model. This framework provides a simple description of multi-soliton solutions in a harmonic trap, showing excellent agreement with numerical simulations for both integrable and non-integrable cases.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Multidisciplinary
Yichen Huang, Joel E. Moore
Summary: We study the representational power of Boltzmann machines in quantum many-body systems and prove that any local tensor network state can be represented by a local neural network. Despite difficulties in representing chiral topological states using local tensor networks, we successfully construct a quasilocal neural network representation for a chiral p-wave superconductor, demonstrating the strength of Boltzmann machines.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Kai Klocke, Joel E. Moore, Jason Alicea, Gabor B. Halasz
Summary: Recent theoretical studies have shown the nontrivial impact of phonons on the thermal Hall conductivity of chiral topological phases. This study introduces mixed mesoscopic-macroscopic devices that allow refined thermal-transport probes of non-Abelian spin liquids with Ising topological order.
Article
Physics, Multidisciplinary
Cyrus E. Dreyer, Sinisa Coh, Massimiliano Stengel
Summary: In clean conductors, nonadiabatic Born effective charges are well defined in the low-frequency limit, and the sublattice sum of these charges is proportional to the Drude weight.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Tiancong Zhu, Wei Ruan, Yan-Qi Wang, Hsin-Zon Tsai, Shuopei Wang, Canxun Zhang, Tianye Wang, Franklin Liou, Kenji Watanabe, Takashi Taniguchi, Jeffrey B. Neaton, Alexander Weber-Bargioni, Alex Zettl, Z. Q. Qiu, Guangyu Zhang, Feng Wang, Joel E. Moore, Michael F. Crommie
Summary: The authors used scanning tunnelling microscopy and spectroscopy to study the mirror twin boundaries in single-layer 1H-MoSe2 devices. By adjusting the electron density, they successfully visualized the electronic structure of the mirror twin boundaries and confirmed the presence of density wave excitations and spin-charge separation effects, in agreement with the predictions of the Tomonaga-Luttinger liquid theory.
Article
Physics, Multidisciplinary
Luca Chirolli, Norman Y. Yao, Joel E. Moore
Summary: The hybrid architecture proposed in this Letter combines a superconducting qubit with a topologically protected Majorana memory, enabling the combination of fast gates and long-lived quantum memories.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Kevin Moseni, Richard B. Wilson, Sinisa Coh
Summary: We find that in BaTiO3, the phonon angular momentum is primarily oriented perpendicular to the electrical polarization. Therefore, the external electric field in ferroelectric BaTiO3 not only controls the direction of electrical polarization but also influences the direction of the phonon angular momentum. This discovery opens up the possibility of electric field control of physical phenomena dependent on phonon angular momentum. We have developed an intuitive model based on first-principles calculations to explain the relationship between phonon angular momentum and electric polarization.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Physics, Multidisciplinary
John Bonini, Shang Ren, David Vanderbilt, Massimiliano Stengel, Cyrus E. Dreyer, Sinisa Coh
Summary: Conventional approaches for lattice dynamics in magnetic systems do not consider the effects of time-reversal-symmetry breaking. Recent studies propose a method that combines the first-order change in forces with atomic velocities to rectify this issue. In this Letter, a first-principles method is developed to calculate the velocity-force coupling in extended solids, and it is shown that the assumption of adiabatic separation can lead to significant errors for splittings of zone-center chiral modes in ferromagnetic CrI3. The accurate description of lattice dynamics requires treating magnons and phonons equally.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Varun Menon, Nicholas E. Sherman, Maxime Dupont, Allen O. Scheie, D. Alan Tennant, Joel E. Moore
Summary: Multipartite entanglement in a many-body quantum system can be witnessed through the quantum Fisher information (QFI), and in this study, it was shown that the finite temperature QFI can be expressed in terms of the system's static structure factor. This allows for the determination of finite temperature scaling of multipartite entanglement and low temperature entanglement depth without the need for the full dynamical response function of the system. The study focused on the 1D spin-21 antiferromagnetic Heisenberg model and found that multipartite entanglement in the Heisenberg chain diverges nontrivially as ln(1/T )3/2. The results have implications for experiments probing entanglement in quantum materials.
Article
Optics
Maxime Dupont, Nicolas Didier, Mark J. Hodson, Joel E. Moore, Matthew J. Reagor
Summary: This article studies the entanglement growth and spread in the QAOA algorithm for solving the MaxCut problem. It finds a volume-law entanglement barrier between the initial and final states. The entanglement spectrum is also investigated in connection with random matrix theory, and the entanglement production is compared with a quantum annealing protocol. The implications of these results for tensor network-based methods relying on low-entanglement are discussed.
Article
Materials Science, Multidisciplinary
Paul Anderson, Yifan Huang, Yuanjun Fan, Sara Qubbaj, Sinisa Coh, Qin Zhou, Claudia Ojeda-Aristizabal
Summary: This study demonstrates the effect of domain walls in multilayer graphene quantum Hall effect through the use of a MEMS actuator and magnetoresistance measurements. The ability to tune these domain walls allows for additional quantum Hall effect plateaus and a discrete and reversible modulation of the current in the device.