scholarly journals Edge states and topological properties of electrons on the bismuth on silicon surface with giant spin-orbit coupling

2014 ◽  
Vol 118 (3) ◽  
pp. 457-466 ◽  
Author(s):  
D. V. Khomitsky ◽  
A. A. Chubanov
Keyword(s):  
Silicon Surface ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Edge States ◽  
Topological Properties

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.

scholarly journals Direct observation of topological edge states in silicon photonic crystals: Spin, dispersion, and chiral routing

2020 ◽  
Vol 6 (10) ◽  
pp. eaaw4137 ◽  
Author(s):  
Nikhil Parappurath ◽  
Filippo Alpeggiani ◽  
L. Kuipers ◽  
Ewold Verhagen
Keyword(s):  
Photonic Crystals ◽  
Quantum Spin ◽  
Orbit Coupling ◽  
Far Field ◽  
Spin Orbit Coupling ◽  
Topological Order ◽  
Spin Orbit ◽  
Edge States ◽  
Linear Dispersion ◽  
Silicon Photonic

Topological protection in photonics offers new prospects for guiding and manipulating classical and quantum information. The mechanism of spin-orbit coupling promises the emergence of edge states that are helical, exhibiting unidirectional propagation that is topologically protected against back scattering. We directly observe the topological states of a photonic analog of electronic materials exhibiting the quantum spin Hall effect, living at the interface between two silicon photonic crystals with different topological order. Through the far-field radiation that is inherent to the states’ existence, we characterize their properties, including linear dispersion and low loss. We find that the edge state pseudospin is encoded in unique circular far-field polarization and linked to unidirectional propagation, thus revealing a signature of the underlying photonic spin-orbit coupling. We use this connection to selectively excite different edge states with polarized light and directly visualize their routing along sharp chiral waveguide junctions.

scholarly journals Topological edge states in correlated honeycomb materials with strong spin-orbit coupling

2016 ◽  
Vol 94 (12) ◽  
Author(s):  
Andrei Catuneanu ◽  
Heung-Sik Kim ◽  
Oguzhan Can ◽  
Hae-Young Kee
Keyword(s):  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Edge States ◽  
Strong Spin

scholarly journals Theory of edge states in systems with Rashba spin-orbit coupling

2004 ◽  
Vol 70 (23) ◽  
Author(s):  
A. Reynoso ◽  
Gonzalo Usaj ◽  
M. J. Sánchez ◽  
C. A. Balseiro
Keyword(s):  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Edge States ◽  
Rashba Spin

Quantum anomalous Hall effect on a square lattice with spin–orbit couplings and an exchange field

2014 ◽  
Vol 92 (5) ◽  
pp. 420-424 ◽  
Author(s):  
Xiaoyong Guo ◽  
Xiaobin Ren ◽  
Guangjie Guo ◽  
Jie Peng
Keyword(s):  
Tight Binding ◽  
Chern Number ◽  
Orbit Coupling ◽  
Square Lattice ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Exchange Field ◽  
Edge States ◽  
Binding Model ◽  
Spatial Direction

We investigate a tight-binding model on a two-dimensional square lattice with three terms: the Rashba spin–orbit coupling, the real amplitude next-nearest spin–orbit coupling, and an exchange field. We calculate the first Chern number to identify band topology. It is found that the Chern number takes the quantized values of C1 = 1, 2 and the chiral edge modes can be obtained. Therefore our model realizes the quantum anomalous Hall (QAH) effect. The Rashba coupling is positive for the QAH phase while the next-nearest coupling is detrimental to it. By increasing the exchange field intensity, the Chern number changes from quantized value 2 to 0. The behavior of the edge states is also studied. Particularly for C1 = 2 case, there are two gapless spin-polarized edge states with the same spin polarization moving in the same spatial direction. This indicates that their appearance is topological rather than accidental.

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