scholarly journals Design and realization of topological Dirac fermions on a triangular lattice

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Maximilian Bauernfeind ◽  
Jonas Erhardt ◽  
Philipp Eck ◽  
Pardeep K. Thakur ◽  
Judith Gabel ◽  
...  
Keyword(s):  
Triangular Lattice ◽  
Quantum Spin ◽  
Spin Orbit Coupling ◽  
Dirac Fermions ◽  
Spin Orbit ◽  
Hexagonal Symmetry ◽  
Tunneling Microscopy ◽  
Heavy Atoms ◽  
Strong Spin ◽  
Quantum Spin Hall

AbstractLarge-gap quantum spin Hall insulators are promising materials for room-temperature applications based on Dirac fermions. Key to engineer the topologically non-trivial band ordering and sizable band gaps is strong spin-orbit interaction. Following Kane and Mele’s original suggestion, one approach is to synthesize monolayers of heavy atoms with honeycomb coordination accommodated on templates with hexagonal symmetry. Yet, in the majority of cases, this recipe leads to triangular lattices, typically hosting metals or trivial insulators. Here, we conceive and realize “indenene”, a triangular monolayer of indium on SiC exhibiting non-trivial valley physics driven by local spin-orbit coupling, which prevails over inversion-symmetry breaking terms. By means of tunneling microscopy of the 2D bulk we identify the quantum spin Hall phase of this triangular lattice and unveil how a hidden honeycomb connectivity emerges from interference patterns in Bloch px ± ipy-derived wave functions.

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 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 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 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 Spin Liquid versus Spin Orbit Coupling on the Triangular Lattice

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Jason Iaconis ◽  
Chunxiao Liu ◽  
Gábor Halász ◽  
Leon Balents
Keyword(s):  
Triangular Lattice ◽  
Quantum Spin ◽  
Orbit Coupling ◽  
Spin Liquid ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Liquid States ◽  
Quantum Spin Liquid ◽  
The Relationship ◽  
Liquid Physics

In this paper, we explore the relationship between strong spin-orbit coupling and spin liquid physics. We study a very general model on the triangular lattice where spin-orbit coupling leads to the presence of highly anisotropic interactions. We use variational Monte Carlo to study both U(1)U(1) quantum spin liquid states and ordered ones, via the Gutzwiller projected fermion construction. We thereby obtain the ground state phase diagram in this phase space. We furthermore consider effects beyond the Gutzwiller wavefunctions for the spinon Fermi surface quantum spin liquid, which are of particular importance when spin-orbit coupling is present.

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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