scholarly journals Magnetotransport in Weyl semimetals in the quantum limit: Role of topological surface states

2016 ◽  
Vol 93 (24) ◽  
Author(s):  
Yuya Ominato ◽  
Mikito Koshino
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hamoon Hedayat ◽  
Davide Bugini ◽  
Hemian Yi ◽  
Chaoyu Chen ◽  
Xingjiang Zhou ◽  
...  

AbstractWe use circular dichroism (CD) in time- and angle-resolved photoemission spectroscopy (trARPES) to measure the femtosecond charge dynamics in the topological insulator (TI) $$\hbox {Bi}_{2}\hbox {Te}_{3}$$ Bi 2 Te 3 . We detect clear CD signatures from topological surface states (TSS) and surface resonance (SR) states. In time-resolved measurements, independently from the pump polarization or intensity, the CD shows a dynamics which provides access to the unexplored electronic evolution in unoccupied states of $$\hbox {Bi}_{2}\hbox {Te}_{3}$$ Bi 2 Te 3 . In particular, we are able to disentangle the unpolarized electron dynamics in the bulk states from the spin-textured TSS and SR states on the femtosecond timescale. Our study demonstrates that photoexcitation mainly involves the bulk states and is followed by sub-picosecond transport to the surface. This provides essential details on intra- and interband scattering in the relaxation process of TSS and SR states. Our results reveal the significant role of SRs in the subtle ultrafast interaction between bulk and surface states of TIs.


Author(s):  
Eduard Devyatov ◽  

Experiments on the study of topological surface states of magnetic and nonmagnetic Weyl semimetals charge transfer are presented. For surface states contribution the stationary and nonstationary Josephson effect realized at superconductortopological semi-metal-superconductor hybrid structures is applied.


Author(s):  
Satyaki Kar ◽  
Arun M. Jayannavar

Recently discovered Weyl semimetals (WSM) have found special place in topological condensed matter studies for they represent first example of massless Weyl fermions found in electronic condensed matter systems. A WSM shows gapless bulk energy spectra with Dirac-like point degeneracies, famously called Weyl nodes, which carry with themselves well defined chiralities and topologically protected chiral charges. One finds the Berry curvature of the Bloch bands to become singular, like in a magnetic monopole, at these Weyl nodes. Moreover, these systems feature topological surface states in the form of open Fermi arcs. In this review, we undergo a concise journey from graphene based Dirac physics to Weyl semimetals: the underlying Hamiltonians, their basic features and their unique response to external electric and magnetic fields in order to provide a basic walk-through of how the Weyl physics unfolded with time starting from the discovery of Graphene.


Nanoscale ◽  
2021 ◽  
Author(s):  
Qing Qu ◽  
Bin Liu ◽  
Hongtao Liu ◽  
Jing Liang ◽  
Jiannong Wang ◽  
...  

The intrinsic activities of SnTe (001) and (111) surfaces with robust topological surface states (TSSs) are superior to that of a (211) surface with fragile or without TSSs, attributing to the enhanced charge transfer between H atoms and TSSs.


2017 ◽  
Vol 95 (16) ◽  
Author(s):  
Victor A. Rogalev ◽  
Tomáš Rauch ◽  
Markus R. Scholz ◽  
Felix Reis ◽  
Lenart Dudy ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mingqiang Gu ◽  
Jiayu Li ◽  
Hongyi Sun ◽  
Yufei Zhao ◽  
Chang Liu ◽  
...  

AbstractThe topological surface states of magnetic topological systems, such as Weyl semimetals and axion insulators, are associated with unconventional transport properties such as nonzero or half-quantized surface anomalous Hall effect. Here we study the surface anomalous Hall effect and its spectral signatures in different magnetic topological phases using both model Hamiltonian and first-principles calculations. We demonstrate that by tailoring the magnetization and interlayer electron hopping, a rich three-dimensional topological phase diagram can be established, including three types of topologically distinct insulating phases bridged by Weyl semimetals, and can be directly mapped to realistic materials such as MnBi2Te4/(Bi2Te3)n systems. Among them, we find that the surface anomalous Hall conductivity in the axion-insulator phase is a well-localized quantity either saturated at or oscillating around e2/2h, depending on the magnetic homogeneity. We also discuss the resultant chiral hinge modes embedded inside the side surface bands as the potential experimental signatures for transport measurements. Our study is a significant step forward towards the direct realization of the long-sought axion insulators in realistic material systems.


2021 ◽  
pp. 2008411
Author(s):  
Jinjun Ding ◽  
Chuanpu Liu ◽  
Yuejie Zhang ◽  
Vijaysankar Kalappattil ◽  
Rui Yu ◽  
...  

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