Disorder effects in InAs/GaSb **topological** **insulator** candidates

5/10 relevant

arXiv

Edelstein and inverse Edelstein effects caused by the pristine surface
states of **topological** **insulators**

**topological**

**insulators**is investigated by means of a semiclassical approach. Expand abstract.

**topological**

**insulators**is investigated by means of a semiclassical approach. The combined effect of random impurity scattering and the spin-momentum locking of the gapless Dirac cone yields a current-induced surface spin accumulation independent from chemical potential and temperature. Through combing the semiclassical approach with the Bloch equation, the inverse Edelstein effect that converts the spin pumping spin current into a charge current is well explained. Consistency of these results with various experiments will be elaborated in detail.

10/10 relevant

arXiv

Joule meets van der Waals: Mechanical dissipation via image potential
states on a **topological** **insulator** surface

**topological**

**insulator**surface. Expand abstract.

**topological**

**insulator**surfaces of Bi2Te3, where common Joule dissipation was observed to be suppressed due to topologically protected surface states. Thus, a novel type of dissipation mechanism is observed by pendulum AFM, which is related to single electron tunneling resonances into image potential states that are slightly above the Bi2Te3 surface. The application of a magnetic field leads to the break down of the

**topological**protection of the surface states and restores the expected Joule dissipation process. Nanomechanical energy dissipation experienced by the cantilever of pendulum AFM provides a novel source of information on the dissipative nature of the quantum-tunneling phenomena on the

**topological**

**insulator**surface.

8/10 relevant

arXiv

First-principles prediction of a new family of layered **topological**
**insulators**

**topological**

**insulators**(TIs), two strong

**topological**metals (TMs) and nearly twenty trivial

**insulators**at their equilibrium structures. The TIs are in the (1;111)

**topological**class, with energy gaps ranging from 0.04 to 0.2 eV. The strong TMs and the trivial

**insulators**belong to the (1;111) and (0;000)

**topological**classes, respectively. Small compressive strains easily turn some of the trivial

**insulators**into strong TIs. This study enriches not only the family of

**topological**materials but also the family of van der Waals layered materials, providing promising candidates for the future spintronic devices.

10/10 relevant

arXiv

Dirac surface states in intrinsic magnetic **topological** **insulators**
EuSn2As2 and MnBi2nTe3n+1

**topological**

**insulators**(TIs), the interplay between magnetic order and nontrivial topology can induce fascinating

**topologic**al quantum phenomena, such as the quantum anomalous Hall effect, chiral Majorana fermions and axion electrodynamics. Expand abstract.

**topological**

**insulators**(TIs), the interplay between magnetic order and nontrivial topology can induce fascinating

**topological**quantum phenomena, such as the quantum anomalous Hall effect, chiral Majorana fermions and axion electrodynamics. Recently, a great deal of attention has been focused on the intrinsic magnetic TIs, where disorder effects can be eliminated to a large extent, which is expected to facilitate the emergence of

**topological**quantum phenomena. In despite of intensive efforts, experimental evidence of the

**topological**surface states (SSs) remains elusive. Here, by combining first-principles calculations and angle-resolved photoemission spectroscopy (ARPES) experiments, we have revealed that EuSn2As2 is an antiferromagnetic TI with observation of Dirac SSs consistent with our prediction. We also observe nearly gapless Dirac SSs in antiferromagnetic TIs MnBi2nTe3n+1 (n = 1 and 2), which were absent in previous ARPES results. These results provide clear evidence for nontrivial topology of these intrinsic magnetic TIs. Furthermore, we find that the

**topological**SSs show no observable changes across the magnetic transition within the experimental resolution, indicating that the magnetic order has quite small effect on the

**topological**SSs, which can be attributed to weak hybridization between the localized magnetic moments, from either 4f or 3d orbitals, and the

**topological**electronic states. This provides insights for further research that the correlations between magnetism and

**topological**states need to be strengthened to induce larger gaps in the

**topological**SSs, which will facilitate the realization of

**topological**quantum phenomena at higher temperatures.

10/10 relevant

arXiv

Electromagnetic-dual metasurfaces for **topological** states along a
one-dimensional interface

**topological**phases, as well as for applications benefiting the compactness of metasurfaces and the potential of

**topologic**al

**insulators**. Expand abstract.

**topological**

**insulators**has rapidly been followed by the advent of their photonic analogues, motivated by the prospect of backscattering-immune light propagation. So far, however, implementations have mainly relied on engineering bulk modes in photonic crystals and waveguide arrays in two-dimensional systems, which closely mimic their electronic counterparts. In addition, metamaterials-based implementations subject to electromagnetic duality and bianisotropy conditions suffer from intricate designs and narrow operating bandwidths. Here, it is shown that symmetry-protected

**topological**states akin to the quantum spin-Hall effect can be realized in a straightforward manner by coupling surface modes over metasurfaces of complementary electromagnetic responses. Specifically, stacking unit cells of such metasurfaces directly results in double Dirac cones of degenerate transverse-electric and transverse-magnetic modes, which break into a wide non-trivial bandgap at small inter-layer separation. Consequently, the ultrathin structure supports robust gapless edge states, which are confined along a one-dimensional line rather than a surface interface, as demonstrated at microwave frequencies by near field imaging. The simplicity and versatility of the proposed approach proves attractive as a tabletop platform for the study of classical

**topological**phases, as well as for applications benefiting the compactness of metasurfaces and the potential of

**topological**

**insulators**.

6/10 relevant

arXiv

Topological Electronic Structure and Its Temperature Evolution in
Antiferromagnetic **Topological** **Insulator** MnBi2Te4

**topological**

**insulators**were proposed in MnBi2Te4-family compounds - on which rich

**topologic**al effects could be realized under much relaxed experimental conditions. Expand abstract.

**Topological**quantum materials coupled with magnetism can provide a platform for realizing rich exotic physical phenomena, including quantum anomalous Hall effect, axion electrodynamics and Majorana fermions. However, these unusual effects typically require extreme experimental conditions such as ultralow temperature or sophisticate material growth and fabrication. Recently, new intrinsic magnetic

**topological**

**insulators**were proposed in MnBi2Te4-family compounds - on which rich

**topological**effects could be realized under much relaxed experimental conditions. However, despite the exciting progresses, the detailed electronic structures observed in this family of compounds remain controversial up to date. Here, combining the use of synchrotron and laser light sources, we carried out comprehensive and high resolution angle-resolved photoemission spectroscopy studies on MnBi2Te4, and clearly identified its

**topological**electronic structures including the characteristic gapless

**topological**surface states. In addition, the temperature evolution of the energy bands clearly reveals their interplay with the magnetic phase transition by showing interesting differences for the bulk and surface states, respectively. The identification of the detailed electronic structures of MnBi2Te4 will not only help understand its exotic properties, but also pave the way for the design and realization of novel phenomena and applications.

8/10 relevant

arXiv

Conduction of surface electrons in a **topological** **insulator** with spatially random magnetization

**topological**

**insulators**in the presence of a correlated random exchange field. Expand abstract.

**topological**

**insulators**in the presence of a correlated random exchange field. Such an exchange field may be due to random magnetization with correlated fluctuations. We determine the relaxation time due to scattering from the magnetization fluctuations and from other structural defects. Then we calculate the longitudinal charge conductivity taking into account the contribution due to vertex correction.

8/10 relevant

arXiv

Exploring **Topological** Superconductivity in **Topologic**al Materials

**topological**superconductors and induced superconductivity in

**topologic**al

**insulators**or semimetals as well as artificial structures. Expand abstract.

**topological**superconductivity and Majorana zero modes has become a rapidly developing field. Many types of proposals to realize

**topological**superconductors have been presented, and significant advances have been recently made. In this review, we conduct a survey on the experimental progress in possible

**topological**superconductors and induced superconductivity in

**topological**

**insulators**or semimetals as well as artificial structures. The approaches to inducing superconductivity in

**topological**materials mainly include high pressure application, the hard-tip point contact method, chemical doping or intercalation, the use of artificial

**topological**superconductors, and electric field gating. The evidence supporting

**topological**superconductivity and signatures of Majorana zero modes are also discussed and summarized.

4/10 relevant

arXiv

Pseudospin-Polarized **Topological** Line Defects in Dielectric Photonic
Crystals

**topological**

**insulators**have been explored extensively due to the robust edge states they support. Expand abstract.

**topological**

**insulators**have been explored extensively due to the robust edge states they support. In this work, we propose a

**topological**electromagnetic system based on a line defect in topologically nontrivial photonic crystals (PCs). With a finite-difference supercell approach, modal analysis of the PCs structure is investigated in detail. The

**topological**line-defect states are pseudospin polarized and their energy flow directions are determined by the corresponding pseudospin helicities. These states can be excited by using two spatially-symmetric line-source arrays carrying orbital angular momenta. The feature of the unidirectional propagation is demonstrated and it is stable when disorders are introduced to the PCs structure.

4/10 relevant

arXiv