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Related papers: Valley polarization braiding in strained graphene

200 papers

Inspired by recent progress in fabricating precisely zigzag-edged graphene nanoribbons and the observation of edge magnetism, we find that spin polarized edge modes with well-defined valley index can exist in a bulk energy gap opened by a…

Materials Science · Physics 2011-11-16 Zhenhua Qiao , Yugui Yao , Shengyuan A. Yang , Bin Wang , Qian Niu

Achieving a population imbalance between the two inequivalent valleys is a critical first step for any valleytronic device. A valley-polarization can be induced in biased bilayer graphene using circularly polarized light. In this paper, we…

Mesoscale and Nanoscale Physics · Physics 2021-02-17 Alex Friedlan , Marc M. Dignam

Introducing quantum confinement has uncovered a rich set of interesting quantum phenomena and allows one to directly probe the physics of confined (quasi-)particles. In most experiments, however, electrostatic potential is the only…

Mesoscale and Nanoscale Physics · Physics 2024-03-08 Ya-Ning Ren , Yu-Chen Zhuang , Qing-Feng Sun , Lin He

Chirally stacked N-layer graphene systems with N >= 2 exhibit a variety of distinct broken symmetry states in which charge density contributions from different spins and valleys are spontaneously transferred between layers. We explain how…

Strongly Correlated Electrons · Physics 2013-07-02 Fan Zhang , Jeil Jung , Gregory A. Fiete , Qian Niu , Allan H. MacDonald

Graphene, and other members of the monolayer Xene family, represent an ideal materials platform for "valleytronics", the control of valley localized charge excitations. The absence of a gap in these semi-metals, however, precludes valley…

We propose a simple, yet highly efficient and robust device for producing valley polarized current in graphene. The device comprises of two distinct components; a region of uniform uniaxial strain, adjacent to an out-of-plane magnetic…

Mesoscale and Nanoscale Physics · Physics 2010-08-06 T. Fujita , M. B. A. Jalil , S. G. Tan

Quantum electron transport in side-gated graphene Hall bars is investigated in the presence of quantizing external magnetic fields. The asymmetric potential of four side-gates distorts the otherwise flat bands of the relativistic Landau…

Mesoscale and Nanoscale Physics · Physics 2017-04-26 M. D. Petrović , F. M. Peeters

Deformations in graphene systems are central elements in the novel field of {\it straintronics}. Various strain geometries have been proposed to produce specific properties but their experimental realization has been limited. Because…

Mesoscale and Nanoscale Physics · Physics 2016-09-20 R. Carrillo-Bastos , C. León , D. Faria , A. Latgé , Eva Y. Andrei , N. Sandler

Interacting electrons in flat bands give rise to a variety of quantum phases. One fundamental aspect of such states is the ordering of the various flavours - such as spin or valley - that the electrons can undergo and the excitation…

Mesoscale and Nanoscale Physics · Physics 2023-05-17 Gelareh Farahi , Cheng-Li Chiu , Xiaomeng Liu , Zlatko Papic , Kenji Watanabe , Takashi Taniguchi , Michael P. Zaletel , Ali Yazdani

We study the low energy edge states of bilayer graphene in a strong perpendicular magnetic field. Several possible simple boundaries geometries related to zigzag edges are considered. Tight-binding calculations reveal three types of edge…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 Victoria Mazo , Efrat Shimshoni , Herbert A. Fertig

We numerically study the quantum Hall effect in biased bilayer graphene based on a tight-binding model in the presence of disorder. Integer quantum Hall plateaus with quantized conductivity $\sigma_{xy}=\nu e^2/h$ (where $\nu$ is any…

Mesoscale and Nanoscale Physics · Physics 2009-07-29 R. Ma , L. J. Zhu , L. Sheng , M. Liu , D. N. Sheng

Graphene properties can be manipulated by a periodic potential. Based on the tight-binding model, we study graphene under a one-dimensional (1D) modulated magnetic field which contains both a uniform and a staggered component. New chiral…

Strongly Correlated Electrons · Physics 2011-01-18 Lei Xu , Jin An , Chang-De Gong

We study the density of states in graphene at high magnetic field, when the physics is dominated by strong correlations between electrons. In particular we use the method of Haldane pseudopotentials to focus on almost empty or almost filled…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Lih-King Lim , M. O. Goerbig , Cristina Bena

The edges of graphene and graphene like systems can host localized states with evanescent wave function with properties radically different from those of the Dirac electrons in bulk. This happens in a variety of situations, that are…

Mesoscale and Nanoscale Physics · Physics 2016-09-20 J. L. Lado , N. Garcia-Martinez , J. Fernandez-Rossier

While usual edge states in the quantum Hall effect(QHE) reside between adjacent Landau levels, QHE in graphene has a peculiar edge mode at E=0 that reside right within the n=0 Landau level as protected by the chiral symmetry. We have…

Mesoscale and Nanoscale Physics · Physics 2008-11-04 Mitsuhiro Arikawa , Yasuhiro Hatsugai , Hideo Aoki

Spatially varying strained graphene can acquire interesting electronic properties because of the strain-induced valley-dependent gauge (pseudomagnetic) fields1,2. Here we report the realization of strained graphene regions located close to…

Materials Science · Physics 2015-03-31 Jun-Fang Liu , Ke-Ke Bai , Jia-Bin Qiao , Yu Zhou , Jia-Cai Nie , Hailin Peng , Zhongfan Liu , Lin He

The magnetic field dependence of energy levels in gapped single- and bilayer graphene quantum dots (QDs) defined by electrostatic gates is studied analytically in terms of the Dirac equation. Due to the absence of sharp edges in these types…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Patrik Recher , Johan Nilsson , Guido Burkard , Bjoern Trauzettel

When twisted to angles near 1{\deg}, graphene multilayers provide a new window on electron correlation physics by hosting gate-tuneable strongly-correlated states, including insulators, superconductors, and unusual magnets. Here we report…

Coupled electron-hole states are realized in a system consisting of a combination of an electrostatic potential barrier and ring-shaped potential well, which resembles a circular dipole. A perpendicular magnetic field induces confined…

Mesoscale and Nanoscale Physics · Physics 2019-04-05 R. Van Pottelberge , F. M. Peeters

We study theoretically the electron current across a monolayer graphene/hexagonal boron nitride/bilayer graphene tunnelling junction in an external magnetic field perpendicular to the layers. We show that change in effective tunnelling…

Mesoscale and Nanoscale Physics · Physics 2019-02-18 J. J . P. Thompson , D. J. Leech , M. Mucha-Kruczyński