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 Random Rashba spin-orbit coupling at the quantum spin Hall edge

2014 ◽  
Vol 89 (23) ◽  
Author(s):  
Florian Geissler ◽  
François Crépin ◽  
Björn Trauzettel
Keyword(s):  
Quantum Spin ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Rashba Spin ◽  
Quantum Spin Hall

scholarly journals Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit coupling

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Miao Zhou ◽  
Wenmei Ming ◽  
Zheng Liu ◽  
Zhengfei Wang ◽  
Yugui Yao ◽  
...  
Keyword(s):  
Energy Gap ◽  
Quantum Spin ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Quantum Spin Hall

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 Ultrathin two-dimensional superconductivity with strong spin–orbit coupling

2016 ◽  
Vol 113 (38) ◽  
pp. 10513-10517 ◽  
Author(s):  
Hyoungdo Nam ◽  
Hua Chen ◽  
Tijiang Liu ◽  
Jisun Kim ◽  
Chendong Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Gap ◽  
Scanning Tunneling Spectroscopy ◽  
Orbit Coupling ◽  
Spin Splitting ◽  
Scanning Tunneling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Critical Magnetic Fields ◽  
Strong Spin

We report on a study of epitaxially grown ultrathin Pb films that are only a few atoms thick and have parallel critical magnetic fields much higher than the expected limit set by the interaction of electron spins with a magnetic field, that is, the Clogston–Chandrasekhar limit. The epitaxial thin films are classified as dirty-limit superconductors because their mean-free paths, which are limited by surface scattering, are smaller than their superconducting coherence lengths. The uniformity of superconductivity in these thin films is established by comparing scanning tunneling spectroscopy, scanning superconducting quantum interference device (SQUID) magnetometry, double-coil mutual inductance, and magneto-transport, data that provide average superfluid rigidity on length scales covering the range from microscopic to macroscopic. We argue that the survival of superconductivity at Zeeman energies much larger than the superconducting gap can be understood only as the consequence of strong spin–orbit coupling that, together with substrate-induced inversion-symmetry breaking, produces spin splitting in the normal-state energy bands that is much larger than the superconductor’s energy gap.

scholarly journals Films based on group IV–V–VI elements for the design of a large-gap quantum spin Hall insulator with tunable Rashba splitting

RSC Advances ◽  
2017 ◽  
Vol 7 (19) ◽  
pp. 11636-11643 ◽  
Author(s):  
Yi-zhen Jia ◽  
Wei-xiao Ji ◽  
Chang-wen Zhang ◽  
Shu-feng Zhang ◽  
Ping Li ◽  
...  
Keyword(s):  
Topological Insulators ◽  
Quantum Spin ◽  
Group Iv ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Rashba Spin ◽  
Significant Interest ◽  
Potential Applications ◽  
Quantum Spin Hall

Rashba spin–orbit coupling (SOC) in topological insulators (TIs) has recently attracted significant interest due to its potential applications in spintronics.

scholarly journals Deconfinement of Mott localized electrons into topological and spin–orbit-coupled Dirac fermions

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
José M. Pizarro ◽  
Severino Adler ◽  
Karim Zantout ◽  
Thomas Mertz ◽  
Paolo Barone ◽  
...  
Keyword(s):  
Phase Transition ◽  
Tricritical Point ◽  
Density Wave ◽  
Wave Pattern ◽  
Quantum Spin ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Dirac Fermions ◽  
Spin Orbit ◽  
Quantum Spin Hall

Abstract The interplay of electronic correlations, spin–orbit coupling and topology holds promise for the realization of exotic states of quantum matter. Models of strongly interacting electrons on honeycomb lattices have revealed rich phase diagrams featuring unconventional quantum states including chiral superconductivity and correlated quantum spin Hall insulators intertwining with complex magnetic order. Material realizations of these electronic states are, however, scarce or inexistent. In this work, we propose and show that stacking 1T-TaSe2 into bilayers can deconfine electrons from a deep Mott insulating state in the monolayer to a system of correlated Dirac fermions subject to sizable spin–orbit coupling in the bilayer. 1T-TaSe2 develops a Star-of-David charge density wave pattern in each layer. When the Star-of-David centers belonging to two adyacent layers are stacked in a honeycomb pattern, the system realizes a generalized Kane–Mele–Hubbard model in a regime where Dirac semimetallic states are subject to significant Mott–Hubbard interactions and spin–orbit coupling. At charge neutrality, the system is close to a quantum phase transition between a quantum spin Hall and an antiferromagnetic insulator. We identify a perpendicular electric field and the twisting angle as two knobs to control topology and spin–orbit coupling in the system. Their combination can drive it across hitherto unexplored grounds of correlated electron physics, including a quantum tricritical point and an exotic first-order topological phase transition.

scholarly journals Spin-Orbit Coupling and Quantum Spin Hall Effect for Neutral Atoms without Spin Flips

2013 ◽  
Vol 111 (22) ◽  
Author(s):  
Colin J. Kennedy ◽  
Georgios A. Siviloglou ◽  
Hirokazu Miyake ◽  
William Cody Burton ◽  
Wolfgang Ketterle
Keyword(s):  
Hall Effect ◽  
Quantum Spin ◽  
Spin Hall Effect ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Neutral Atoms ◽  
Quantum Spin Hall Effect ◽  
Spin Flips ◽  
Quantum Spin Hall

scholarly journals Dumbbell stanane: a large-gap quantum spin hall insulator

2015 ◽  
Vol 17 (25) ◽  
pp. 16624-16629 ◽  
Author(s):  
Xin Chen ◽  
Linyang Li ◽  
Mingwen Zhao
Keyword(s):  
Coupling Effect ◽  
Quantum Spin ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Quantum Spin Hall

Hydrogenating DB stanene improves its stability and spin–orbit coupling effect, leading to a stable large-gap quantum spin Hall insulator.

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