Article
Chemistry, Multidisciplinary
Simon Munyan, Arman Rashidi, Alexander C. Lygo, Robert Kealhofer, Susanne Stemmer
Summary: In this study, edge modes in the 2D TI phase of Cd3As2 are characterized using a quantum point contact device, and their controllable transmission is investigated, which is crucial for future applications in quantum interference devices.
Article
Materials Science, Multidisciplinary
Loredana M. Vasiloiu, Apoorv Tiwari, Jens H. Bardarson
Summary: This study investigates the coherence times of Majorana zero modes in different scenarios by explicitly computing their closed form expressions in models of various dimensional superconductors. The results show enhanced coherence times for a certain class of Majorana operators under specific dissipative dynamics, while the coherence of the remaining operators decays much faster. Additionally, the numerical simulations demonstrate the robustness of the coherence times to the presence of disorder.
Article
Materials Science, Multidisciplinary
Simon Wozny, Martin Leijnse, Sigurdur Erlingsson
Summary: When driven periodically, increasing the potential energy contribution of magnetic impurities closes the density of states (DOS) gap in two-dimensional topological insulators and leads to the closure of the transmission gap as well. The asymmetry in energy function indicates potential valuable information about the magnetic impurities from the dynamical transport properties.
Article
Chemistry, Multidisciplinary
Gennady M. Gusev, Ze D. Kvon, Alexander D. Levin, Nikolay N. Mikhailov
Summary: The thermoelectric response of 80 nm-thick strained HgTe films in a three-dimensional topological insulator was experimentally studied. An ambipolar thermopower was observed, with the Fermi energy shifting from the conduction band to the valence band. The comparison between theory and experiment showed that the thermopower was mainly due to phonon drag contribution, and the Seebeck coefficient was modified in the region where 2D Dirac electrons coexisted with bulk hole states due to electron-hole scattering.
Article
Optics
Yu-Biao Wu, Guang-Can Guo, Zhen Zheng, Xu-Bo Zou
Summary: The proposal introduces a method for synthesizing higher-order topological superfluids that support various Majorana zero modes in ultracold atomic gases. By using a two-dimensional optical superlattice that modulates spin-orbit coupling spatially, different topological phase transitions among trivial superfluids, first-order and second-order topological superfluids are identified with respect to experimentally tunable parameters.
Article
Optics
Zhaojian Zhang, Junbo Yang, Te Du, Xinpeng Jiang
Summary: This study demonstrates that properly designed supercell metasurfaces can support photonic corner states and serve as an ideal platform for topological polaritons and reconfigurable corner states. The robustness of the corner state and strong coupling are revealed by introducing defects into the metasurface. By assembling two-dimensional materials onto the metasurface, tunable corner states and strong coupling with on-demand control are achieved. The proposed hybrid-material platform holds great potential for practical topological applications.
PHOTONICS RESEARCH
(2022)
Article
Physics, Multidisciplinary
L. S. Braginsky, M. Entin
Summary: The magnetoresistance theory of the edge state of a two-dimensional topological insulator is developed, where the magnetic field violates the time reversal invariance. Magnetoresistance arises due to the energy gap opened by a magnetic field, and the combined action of impurities and magnetic field causes the backscattering of edge electrons. Although impurities are necessary for scattering, a sufficiently strong interaction with impurities leads to backscattering suppression.
Article
Physics, Condensed Matter
Teresa Lee, Gun Sang Jeon
Summary: We studied the energy band structure of two-dimensional honeycomb-lattice topological insulators with edge exchange couplings for electrons. The energy dispersion of the edge states was found to depend strongly on the direction of the exchange couplings. Energy band splitting occurred when the exchange couplings were perpendicular to the plane of the topological insulators. In contrast, parallel exchange couplings generated a finite energy gap in the edge-state bands for zigzag edges, while armchair nanoribbons did not show such energy gaps. We also discussed the dependence of energy band structures of edge states on the magnetic structure of exchange couplings and the effects of disorder on the edge-state density of states.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Chemistry, Multidisciplinary
Shu Hsuan Su, Pei-Yu Chuang, Hsin-Yu Chen, Shih-Chang Weng, Wei-Chuan Chen, Ku-Ding Tsuei, Chao-Kuei Lee, Shih-Hsun Yu, Mitch M-C Chou, Li-Wei Tu, Horng-Tay Jeng, Chien-Ming Tu, Chih-Wei Luo, Cheng-Maw Cheng, Tay-Rong Chang, Jung-Chun Andrew Huang
Summary: The study demonstrates the topological proximity effect between antimonene and Sb2Te3, indicating the 2D material antimonene possesses a 2D topological state and forms Dirac fermions at the interface of a 2D normal insulator and a 3D topological insulator. By hydrogen etching Sb2Te3, the position of the Dirac point and shape of the Dirac surface state can be tuned, providing a new approach to create QSH systems in 2D-material TI heterostructures.
Article
Physics, Multidisciplinary
Shuo Liu, Shaojie Ma, Ruiwen Shao, Lei Zhang, Biao Yang, Miguel Navarro-Cia, Tie Jun Cui, Shuang Zhang
Summary: This study identified a special type of edge state that can appear in a 1D electrical circuit and its position relative to the bulk bands is determined by the intersections of specific critical frequencies.
NEW JOURNAL OF PHYSICS
(2021)
Article
Chemistry, Physical
Nana Shumiya, Md Shafayat Hossain, Jia-Xin Yin, Zhiwei Wang, Maksim Litskevich, Chiho Yoon, Yongkai Li, Ying Yang, Yu-Xiao Jiang, Guangming Cheng, Yen-Chuan Lin, Qi Zhang, Zi-Jia Cheng, Tyler A. Cochran, Daniel Multer, Xian P. Yang, Brian Casas, Tay-Rong Chang, Titus Neupert, Zhujun Yuan, Shuang Jia, Hsin Lin, Nan Yao, Luis Balicas, Fan Zhang, Yugui Yao, M. Zahid Hasan
Summary: This study provides micro-spectroscopic evidence for the presence of a room-temperature quantum spin Hall edge state on the surface of a higher-order topological insulator. The research reveals the microstructural features of the topological phase and suggests further exploration of high-temperature transport quantization.
Article
Multidisciplinary Sciences
J. Reimann, K. Sumida, M. Kakoki, K. A. Kokh, O. E. Tereshchenko, A. Kimura, J. Guedde, U. Hoefer
Summary: We investigated the ultrafast population dynamics of Sb2Te3 in two-dimensional momentum space using time-and angle-resolved two-photon photoemission spectroscopy. By using linearly polarized mid-infrared pump pulses, we were able to directly excite the material across the Dirac point. Our experiments revealed a strong enhancement of this resonant excitation within the Dirac cone along three specific directions, resulting in a macroscopic photocurrent when the plane of incidence is aligned in a certain direction. We also demonstrated that doping the Sb2Te3 with vanadium atoms significantly enhances inelastic electron scattering while having minimal impact on elastic scattering near the Dirac cone.
SCIENTIFIC REPORTS
(2023)
Article
Physics, Applied
Guangchen He, Yao Qin, Qifu Wang, Chengxin Cai
Summary: An elastic topological insulator with pseudo-spin characteristics is designed by introducing a positive hexagonal carrier in honeycomb lattice phononic crystals. Symmetry breaking is achieved to open a four-fold Dirac point and form a band gap, leading to the emergence of topological edge states.
MODERN PHYSICS LETTERS B
(2022)
Article
Chemistry, Multidisciplinary
Huanhuan Yang, Lingling Song, Yunshan Cao, Peng Yan
Summary: We experimentally realized a 2D weak topological insulator in spinless Su-Schrieffer-Heeger circuits with parity-time and chiral symmetries. By modulating centrosymmetric circuit deformations, we observed a Dirac semimetal phase and four weak topological insulator phases. Our work provides the first experimental evidence for 2D weak topological insulators and advances our understanding of topological insulators, flat bands, and the features of Dirac cones.
Article
Multidisciplinary Sciences
Rui Wang, Tigran A. Sedrakyan, Baigeng Wang, Lingjie Du, Rui-Rui Du
Summary: Correlation and frustration are important in physics, leading to new quantum phases. In this study, we observe the moat-band phenomena in shallowly inverted InAs/GaSb quantum wells, where we find an unconventional time-reversal-symmetry breaking excitonic ground state. We demonstrate the evolution from helical-like to chiral-like edge transport and explain our experimental observations using a moat band for excitons that results from density imbalance.
Review
Physics, Multidisciplinary
Michael Moskalets, Janne Kotilahti, Pablo Burset, Christian Flindt
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2020)
Review
Materials Science, Multidisciplinary
Dimitrie Culcer, Aydin Cem Keser, Yongqing Li, Grigory Tkachov
Article
Physics, Multidisciplinary
Janne Kotilahti, Pablo Burset, Michael Moskalets, Christian Flindt
Summary: Research has shown that injecting multi-particle pulses can lead to the observation of multi-particle effects in an electronic Mach-Zehnder interferometer, with each particle in the pulse contributing independently to the interference current while the interference visibility exhibits a Fraunhofer-like diffraction pattern.
Article
Chemistry, Multidisciplinary
Andreas Sinner, Gregor Tkachov
Summary: This study proposes an analytical approach to the conductivity of disordered graphene sheets in a perpendicular magnetic field based on the analysis of diffusive processes. The obtained results, including the density of states, diffusion coefficient, and static conductivity, are not only interesting from a theoretical perspective but also have practical significance for the development of high-precision calibration devices.
Article
Physics, Condensed Matter
Andreas Sinner, Gregor Tkachov
Summary: In this study, we investigate the electronic transport in two-dimensional semimetals placed in a homogeneous magnetic field. The zero energy Landau modes, arising from the material's intrinsic Berry curvature, are found to play a crucial role in determining the density of states and static conductivity of the disordered system. We develop an analytical approach based on the mean-squared displacement to study diffusion and conductivity.
EUROPEAN PHYSICAL JOURNAL B
(2022)
Article
Chemistry, Multidisciplinary
Lucia Vigliotti, Alessio Calzona, Niccolo Traverso Ziani, F. Sebastian Bergeret, Maura Sassetti, Bjoern Trauzettel
Summary: Josephson junctions in the presence of a magnetic field can exhibit different interference patterns based on the spatial distribution of the supercurrent. In this study, a topological Josephson junction is investigated with extended edge states. It is found that the interference pattern, driven by dominant crossed Andreev reflections and overlapped edge states, approaches a periodicity of 2 phi(0).
Article
Physics, Multidisciplinary
Aritra Lahiri, Sang -Jun Choi, Bjoern Trauzettel
Summary: Josephson tunnel junctions exhibit a supercurrent proportional to the sine of the superconducting phase difference. Voltage pulses with sharp temporal variations significantly influence the term proportional to the cosine of the phase difference. The nonequilibrium fractional Josephson effect arises from the interference of nonequilibrium virtual quasiparticle excitations, and it is independent of the ground state fermion parity in topological Josephson junctions.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Applied
Xue Yang, Pablo Burset, Bo Lu
Summary: In a four-terminal setup, researchers found that a quantum spin Hall strip with different edges contacted by s-wave superconductors can exhibit Majorana bound states protected by time-reversal symmetry. They observed a subharmonic gap structure in the conductance peaks from multiple Andreev reflections, which is sensitive to the phase difference between the superconductors. This phase difference also controls an even-odd effect, where odd spikes disappear and even spikes split when the Majorana states form or when the superconductors have different gap sizes.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Bo Lu, Satoshi Ikegaya, Pablo Burset, Yukio Tanaka, Naoto Nagaosa
Summary: In this study, it is theoretically demonstrated that a superconductor-normal metal-superconductor Josephson junction diode on the two-dimensional surface of a topological insulator has large tunability.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Michael Krebsbach, Bjoern Trauzettel, Alessio Calzona
Summary: This study provides an in-depth analysis of the relevant parameters of Richardson extrapolation and proposes an optimized protocol for its implementation. It allows for precise control of statistical uncertainty and shows a significant improvement in error mitigation performance.
Article
Materials Science, Multidisciplinary
Bo Lu, Guanxin Cheng, Pablo Burset, Yukio Tanaka
Summary: This study investigates the conductance of a metal probe in direct contact with the helical edge modes of a quantum spin Hall insulator (QSHI). It shows that a conductance peak of 2e2/h and 4e2/h occurs at zero temperature in QSHI-based superconductor-ferromagnet hybrids and Josephson junctions hosting Majorana bound states (MBSs), respectively. The conductance quantization is robust to changes in system parameters and remains unchanged even with increasing distance between the probe and MBSs.
Article
Materials Science, Multidisciplinary
Jorge Cayao, Paramita Dutta, Pablo Burset, Annica M. Black -Schaffer
Summary: This study investigates the impact of Cooper pair symmetries on the electron transport in a finite-size topological Josephson junction at the edge of a two-dimensional topological insulator in proximity to conventional superconductors. The research reveals that due to the finite junction size, electron transport can be highly tunable by the superconducting phase difference across the junction. The study also uncovers an interesting behavior where odd-frequency Cooper pairs become the only type of pairing inside the topological junction that contribute to transport, offering a highly tunable detection scheme for odd-frequency Cooper pairs.
Article
Materials Science, Multidisciplinary
Jorge Cayao, Pablo Burset
Summary: Quasi-zero-energy states can form naturally in any superconducting hybrid junction due to confinement effects, independent of spin fields and topology. These topologically trivial quasi-zero-energy states produce zero-bias conductance peaks similar to Majorana signatures, but with different peak height and stability characteristics.
Article
Physics, Condensed Matter
G. Tkachov
Summary: This paper explores the theoretical boundary states in single-layer WSe2 and its potential applications in topological electronics. By analyzing the behavior of boundary states and the characteristics of spectrum termination points, it is possible to understand the electrical and thermal properties at the phase boundary. The research reveals that the thermopower exhibits ambipolar behavior in the bandgap of 1T'-WSe2.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
Bo Lu, Pablo Burset, Yukio Tanaka
