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Related papers: Valley-Polarized Metals and Quantum Anomalous Hall…

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In graphene, the pseudospin and the valley flavor arise as new types of quantum degrees of freedom due to the honeycomb lattice comprising two sublattices (A and B) and two inequivalent Dirac points (K and K') in the Brillouin zone,…

Mesoscale and Nanoscale Physics · Physics 2011-12-26 Changwon Park , Heejun Yang , Andrew J. Mayne , Gerald Dujardin , Sunae Seo , Young Kuk , Jisoon Ihm , Gunn Kim

Plumbene, similar to silicene, has a buckled honeycomb structure with a large band gap ($\sim 400$ meV). All previous studies have shown that it is a normal insulator. Here, we perform first-principles calculations and employ a sixteen-band…

Materials Science · Physics 2017-03-28 Xiang-Long Yu , Li Huang , Jiansheng Wu

We propose a new method to identify transitions from a topological insulator to a band insulator in silicene (the silicon equivalent of graphene) in the presence of perpendicular magnetic and electric fields, by using the R\'enyi-Wehrl…

Mesoscale and Nanoscale Physics · Physics 2015-02-25 M. Calixto , E. Romera

Emergence of ferromagnetism in non-magnetic semiconductors is strongly desirable, especially in topological materials thanks to the possibility to achieve quantum anomalous Hall effect. Based on first-principles calculations, we propose…

Mesoscale and Nanoscale Physics · Physics 2016-08-24 Huixia Fu , Zheng Liu , Chao Lian , Jin Zhang , Hui Li , Jia-Tao Sun , Sheng Meng

We report on the fractional quantum Hall states of germanene and silicene where one expects a strong spin-orbit interaction. This interaction causes an enhancement of the electron-electron interaction strength in one of the Landau levels…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 Vadym M. Apalkov , Tapash Chakraborty

We investigate the effect of spin-orbit coupling on the band structure of graphene-based two-dimensional Dirac fermion gases in the quantum Hall regime. Taking monolayer graphene as our first candidate, we show that a quantum phase…

Mesoscale and Nanoscale Physics · Physics 2013-06-11 Pierre Carmier , Oleksii Shevtsov , Christoph Groth , Xavier Waintal

We establish that the interplay of itinerant fermions with localized magnetic moments on a checkerboard lattice leads to magnetic flux-phases. For weak itineracy the flux-phase is coplanar and the electronic dispersion takes the shape of…

Strongly Correlated Electrons · Physics 2015-06-04 Jörn W. F. Venderbos , Maria Daghofer , Jeroen van den Brink , Sanjeev Kumar

Monolayer transition metal dichalcogenides have emerged as prominent candidates to explore the complex interplay between the spin and the valleys degrees of freedom. The strong spin-orbit interaction and broken inversion symmetry within…

Quantum anomalous Hall (QAH) insulators with high Chern number (C) enables multiple dissipationless edge channels for low-power-consumption electronics. We report the realization of multiple high-C QAH insulators including C=3,5,6, and 7 in…

When phonons couple to fermions in 2D semimetals, the interaction may turn the system into an insulator. There are several insulating phases in which the time reversal and the sublattice symmetries are spontaneously broken. Examples are…

Strongly Correlated Electrons · Physics 2021-05-12 Andreas Sinner , Klaus Ziegler

The quantum anomalous Hall (QAH) state is a two-dimensional bulk insulator with a non-zero Chern number in absence of external magnetic fields. Protected gapless chiral edge states enable dissipationless current transport in electronic…

Mesoscale and Nanoscale Physics · Physics 2011-08-25 Hai-Jun Zhang , Xiao Zhang , Shou-Cheng Zhang

When one of the graphene layers of Magic Angle Twisted Bilayer Graphene is nearly aligned with its hexagonal boron nitride substrate (a configuration dubbed TBG/hBN), the active electronic bands are nearly flat, and have a Chern number…

Strongly Correlated Electrons · Physics 2019-12-25 Cécile Repellin , T. Senthil

Silicene systems, due to the buckled structure of the lattice, manifest remarkable intrinsic spin-orbit interaction triggering a topological phase transition in the low-energy regime. Thus, we found that protected edge states are present in…

Mesoscale and Nanoscale Physics · Physics 2015-03-18 P. Rakyta , M. Vigh , A. Csordás , J. Cserti

We present a microscopic theory to give a physical picture of the formation of quantum anomalous Hall (QAH) effect in graphene due to a joint effect of Rashba spin-orbit coupling $\lambda_R$ and exchange field $M$. Based on a continuum…

Materials Science · Physics 2012-03-29 Zhenhua Qiao , Hua Jiang , Xiao Li , Yugui Yao , Qian Niu

We present the experimental data of the electric features of the silicon nanosandwichstructures obtained by silicon planar technology in the frameworks of the Hall geometry that represent the ultra-shallow silicon quantum well of 2 nm wide…

Mesoscale and Nanoscale Physics · Physics 2020-12-01 N. I. Rul , N. T. Bagraev , L. E. Klyachkin , A. M. Malyarenko

Topological phases typically encode topology at the level of the single particle band structure. But a remarkable class of models shows that quantum anomalous Hall effects can be driven exclusively by interactions, while the parent…

Strongly Correlated Electrons · Physics 2018-01-11 Mengsu Chen , Hoi-Yin Hui , Sumanta Tewari , V. W. Scarola

In a dilute two-dimensional electron gas, Coulomb interactions can stabilize the formation of a Wigner crystal. Although Wigner crystals are topologically trivial, it has been predicted that electrons in a partially-filled band can break…

Mesoscale and Nanoscale Physics · Physics 2025-03-13 Ruiheng Su , Dacen Waters , Boran Zhou , Kenji Watanabe , Takashi Taniguchi , Ya-Hui Zhang , Matthew Yankowitz , Joshua Folk

In orbital Chern insulators, the chemical potential acts as a tuning knob to reverse chirality in dissipationless edge currents, enabling electric-field control of magnetic order-key for future quantum electronics. Despite the rise of…

Quantized Hall conductance is a generic feature of two dimensional electronic systems with broken time reversal symmetry. In the quantum anomalous Hall state recently discovered in magnetic topological insulators, time reversal symmetry is…

Based on ab initio calculations, we predict that a monolayer of Cr-doped (Bi,Sb)2Te3 and GdI2 heterostructure is a quantum anomalous Hall insulator with a non-trivial band gap up to 38 meV. The principle behind our prediction is that the…

Mesoscale and Nanoscale Physics · Physics 2015-03-19 Gang Xu , Jing Wang , Claudia Felser , Xiao-Liang Qi , Shou-Cheng Zhang