scholarly journals Testing topological protection of edge states in hexagonal quantum spin Hall candidate materials

2018 ◽  
Vol 98 (16) ◽  
Author(s):  
Fernando Dominguez ◽  
Benedikt Scharf ◽  
Gang Li ◽  
Jörg Schäfer ◽  
Ralph Claessen ◽  
...  
Keyword(s):  
Quantum Spin ◽  
Edge States ◽  
Quantum Spin Hall

scholarly journals Finite Size Effects on Helical Edge States in a Quantum Spin-Hall System

2008 ◽  
Vol 101 (24) ◽  
Author(s):  
Bin Zhou ◽  
Hai-Zhou Lu ◽  
Rui-Lin Chu ◽  
Shun-Qing Shen ◽  
Qian Niu
Keyword(s):  
Size Effects ◽  
Finite Size ◽  
Quantum Spin ◽  
Edge States ◽  
Finite Size Effects ◽  
Quantum Spin Hall

scholarly journals Nonlinear Ballistic Response of Quantum Spin Hall Edge States

2021 ◽  
Vol 127 (20) ◽  
Author(s):  
Pankaj Bhalla ◽  
Ming-Xun Deng ◽  
Rui-Qiang Wang ◽  
Lan Wang ◽  
Dimitrie Culcer
Keyword(s):  
Quantum Spin ◽  
Edge States ◽  
Quantum Spin Hall

scholarly journals Optimal Thermoelectricity with Quantum Spin Hall Edge States

2019 ◽  
Vol 123 (18) ◽  
Author(s):  
Daniel Gresta ◽  
Mariano Real ◽  
Liliana Arrachea
Keyword(s):  
Quantum Spin ◽  
Edge States ◽  
Quantum Spin Hall

scholarly journals Designing photonic topological insulators with quantum-spin-Hall edge states using topology optimization

Nanophotonics ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 1363-1369 ◽  
Author(s):  
Rasmus E. Christiansen ◽  
Fengwen Wang ◽  
Ole Sigmund ◽  
Søren Stobbe
Keyword(s):  
Topology Optimization ◽  
Band Gap ◽  
Design Problem ◽  
Topological Insulators ◽  
Quantum Spin ◽  
Edge States ◽  
Unit Cells ◽  
Improved Performance ◽  
Inverse Design Problem ◽  
Quantum Spin Hall

AbstractDesigning photonic topological insulators (PTIs) is highly non-trivial because it requires inversion of band symmetries around the band gap, which was so far done using intuition combined with meticulous trial and error. Here we take a completely different approach: we consider the design of PTIs as an inverse design problem and use topology optimization to maximize the transmission through an edge mode past a sharp bend. Two design domains composed of two different but initially identical C6ν-symmetric unit cells define the geometrical design problem. Remarkably, the optimization results in a PTI reminiscent of the shrink-and-grow approach to quantum-spin-Hall PTIs but with notable differences in the crystal structure as well as qualitatively different band structures and with significantly improved performance as gauged by the band-gap sizes, which are at least 50% larger than in previous designs. Furthermore, we find a directional β-factor exceeding 99% and very low losses for sharp bends. Our approach allows the introduction of fabrication limitations by design and opens an avenue towards designing PTIs with hitherto-unexplored symmetry constraints.

scholarly journals Evidence for a quantum spin Hall phase in graphene decorated with Bi2Te3 nanoparticles

2018 ◽  
Vol 4 (11) ◽  
pp. eaau6915 ◽  
Author(s):  
K. Hatsuda ◽  
H. Mine ◽  
T. Nakamura ◽  
J. Li ◽  
R. Wu ◽  
...  
Keyword(s):  
Scanning Tunneling Spectroscopy ◽  
Quantum Spin ◽  
Orbit Coupling ◽  
Photoelectron Spectra ◽  
Scanning Tunneling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Edge States ◽  
Graphene Devices ◽  
Quantum Spin Hall

Realization of the quantum spin Hall effect in graphene devices has remained an outstanding challenge dating back to the inception of the field of topological insulators. Graphene’s exceptionally weak spin-orbit coupling—stemming from carbon’s low mass—poses the primary obstacle. We experimentally and theoretically study artificially enhanced spin-orbit coupling in graphene via random decoration with dilute Bi2Te3 nanoparticles. Multiterminal resistance measurements suggest the presence of helical edge states characteristic of a quantum spin Hall phase; the magnetic field and temperature dependence of the resistance peaks, x-ray photoelectron spectra, scanning tunneling spectroscopy, and first-principles calculations further support this scenario. These observations highlight a pathway to spintronics and quantum information applications in graphene-based quantum spin Hall platforms.

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