Quantum spin Hall insulator BiXH (XH = OH, SH) monolayers with a large bulk band gap

2018 ◽  
Vol 20 (19) ◽  
pp. 13632-13636 ◽  
Author(s):  
Xing-Kai Hu ◽  
Ji-Kai Lyu ◽  
Chang-Wen Zhang ◽  
Pei-Ji Wang ◽  
Wei-Xiao Ji ◽  
...  
Keyword(s):  
Band Gap ◽  
Topological Insulators ◽  
Room Temperature ◽  
Quantum Spin ◽  
Two Dimensional ◽  
Spintronic Devices ◽  
Large Bulk ◽  
Bulk Band ◽  
Quantum Spin Hall

A large bulk band gap is critical for the application of two-dimensional topological insulators (TIs) in spintronic devices operating at room temperature.

New family of room temperature quantum spin Hall insulators in two-dimensional germanene films

2016 ◽  
Vol 4 (10) ◽  
pp. 2088-2094 ◽  
Author(s):  
Run-wu Zhang ◽  
Wei-xiao Ji ◽  
Chang-wen Zhang ◽  
Sheng-shi Li ◽  
Ping Li ◽  
...  
Keyword(s):  
First Principles ◽  
Topological Insulators ◽  
Room Temperature ◽  
Quantum Spin ◽  
Band Gaps ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
New Family ◽  
Temperature Applications ◽  
Quantum Spin Hall

Based on first-principles calculations, we predict that 2D germanene decorated with ethynyl-derivatives (GeC2X; X = H, F, Cl, Br, I) can be topological insulators with large band-gaps for room-temperature applications.

Quantum spin Hall state in cyanided dumbbell stanene

RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86089-86094 ◽  
Author(s):  
Min Yuan ◽  
Wei-xiao Ji ◽  
Miao-juan Ren ◽  
Ya-ping Wang ◽  
Hui Zhao
Keyword(s):  
High Temperature ◽  
Hall Effect ◽  
Band Gap ◽  
Condensed Matter ◽  
Quantum Spin ◽  
Condensed Matter Physics ◽  
Two Dimensional ◽  
Important Goal ◽  
Quantum Spin Hall Effect ◽  
Quantum Spin Hall

Searching for two-dimensional (2D) quantum spin Hall (QSH) insulators with a large band gap, in which the Quantum spin Hall effect (QSHE) can be observed at high temperature, is an important goal for condensed matter physics researchers.

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 Strain-Induced Quantum Spin Hall Effect in Two-Dimensional Methyl-Functionalized Silicene SiCH3

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 698 ◽  
Author(s):  
Ceng-Ceng Ren ◽  
Wei-Xiao Ji ◽  
Shu-Feng Zhang ◽  
Chang-Wen Zhang ◽  
Ping Li ◽  
...  
Keyword(s):  
Hexagonal Boron Nitride ◽  
Quantum Spin ◽  
Honeycomb Lattice ◽  
Potential Candidate ◽  
Two Dimensional ◽  
Edge States ◽  
Spin Orbital ◽  
Spintronic Devices ◽  
Potential Applications ◽  
Quantum Spin Hall

Quantum Spin Hall (QSH) has potential applications in low energy consuming spintronic devices and has become a researching hotspot recently. It benefits from insulators feature edge states, topologically protected from backscattering by time-reversal symmetry. The properties of methyl functionalized silicene (SiCH3) have been investigated using first-principles calculations, which show QSH effect under reasonable strain. The origin of the topological characteristic of SiCH3, is mainly associated with the s-pxy orbitals band inversion at Γ point, whilst the band gap appears under the effect of spin-orbital coupling (SOC). The QSH phase of SiCH3 is confirmed by the topological invariant Z2 = 1, as well as helical edge states. The SiCH3 supported by hexagonal boron nitride (BN) film makes it possible to observe its non-trivial topological phase experimentally, due to the weak interlayer interaction. The results of this work provide a new potential candidate for two-dimensional honeycomb lattice spintronic devices in spintronics.

scholarly journals Quantum spin Hall insulators and quantum valley Hall insulators of BiX/SbX (X=H, F, Cl and Br) monolayers with a record bulk band gap

2014 ◽  
Vol 6 (12) ◽  
pp. e147-e147 ◽  
Author(s):  
Zhigang Song ◽  
Cheng-Cheng Liu ◽  
Jinbo Yang ◽  
Jingzhi Han ◽  
Meng Ye ◽  
...  
Keyword(s):  
Band Gap ◽  
Quantum Spin ◽  
Bulk Band ◽  
Quantum Spin Hall

scholarly journals Room temperature quantum spin Hall states in two-dimensional crystals composed of pentagonal rings and their quantum wells

2016 ◽  
Vol 8 (4) ◽  
pp. e264-e264 ◽  
Author(s):  
Yandong Ma ◽  
Liangzhi Kou ◽  
Xiao Li ◽  
Ying Dai ◽  
Thomas Heine
Keyword(s):  
Quantum Wells ◽  
Room Temperature ◽  
Quantum Spin ◽  
Two Dimensional ◽  
Hall States ◽  
Quantum Spin Hall

scholarly journals Tunable quantum spin Hall effect via strain in two-dimensional arsenene monolayer

2016 ◽  
Vol 49 (5) ◽  
pp. 055305 ◽  
Author(s):  
Ya-ping Wang ◽  
Chang-wen Zhang ◽  
Wei-xiao Ji ◽  
Run-wu Zhang ◽  
Ping Li ◽  
...  
Keyword(s):  
Hall Effect ◽  
Quantum Spin ◽  
Spin Hall Effect ◽  
Two Dimensional ◽  
Quantum Spin Hall Effect ◽  
Quantum Spin Hall
Sign in / Sign up

Export Citation Format

Share Document