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Related papers: Spin-Valley Beam Splitter in Graphene

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The so called quantum spin Hall phase is a topologically non trivial insulating phase that is predicted to appear in graphene and graphene-like systems. In this work we address the question of whether this topological property persists in…

Mesoscale and Nanoscale Physics · Physics 2015-07-08 N. A. Garcia-Martinez , J. L. Lado , J. Fernandez-Rossier

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

We propose a non-magnetic, pseudospin-based version of a spin valve, in which the pseudospin polarization in neighboring regions of a graphene bilayer is controlled by external gates. Numerical calculations demonstrate a large on-off ratio…

Mesoscale and Nanoscale Physics · Physics 2009-06-18 Pablo San-Jose , Elsa Prada , Edward McCann , Henning Schomerus

Van der Waals (vdW) heterostructures consisting of bilayer graphene (BLG) encapsulated within monolayers of strong spin-orbit semiconductor WS$_2$ or ferromagnetic semiconductor Cr$_2$Ge$_2$Te$_6$ (CGT), are investigated. By performing…

Mesoscale and Nanoscale Physics · Physics 2021-08-18 Klaus Zollner , Jaroslav Fabian

A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field,…

Quantum Physics · Physics 2017-02-22 Matthias M. Dellweg , Carsten Müller

Graphene has emerged as the foremost material for future two-dimensional spintronics due to its tuneable electronic properties. In graphene, spin information can be transported over long distances and, in principle, be manipulated by using…

Strategically combining four structured domains creates the first ever three-way topological energy-splitter; remarkably, this is only possible using a square, or rectangular, lattice, and not the graphene-like structures more commonly used…

Mesoscale and Nanoscale Physics · Physics 2021-06-02 Mehul P. Makwana , Gregory J. Chaplain

Quantum spin Hall effect was first predicted in graphene. However, the weak spin orbit interaction in graphene meant that the search for quantum spin Hall effect in graphene never fructified. In this work we show how to generate the quantum…

Mesoscale and Nanoscale Physics · Physics 2016-12-09 SK Firoz Islam , Colin Benjamin

A variational technique is used to study sublattice symmetry breaking by strong on-site and nearest neighbor interactions in graphene. When interactions are strong enough to break sublattice symmetry, and with relative strengths…

Strongly Correlated Electrons · Physics 2012-09-12 Y. Araki , G. W. Semenoff

We study the electronic transport properties at the intersection of three topological zero-lines as the elementary current partition node that arises in minimally twisted bilayer graphene. Unlike the partition laws of two intersecting…

Mesoscale and Nanoscale Physics · Physics 2020-09-02 Tao Hou , Yafei Ren , Yujie Quan , Jeil Jung , Wei Ren , Zhenhua Qiao

Monolayer transition-metal dichalcogenides possess a pair of degenerate helical valleys in the band structure that exhibit fascinating optical valley polarization. Optical valley polarization, however, is limited by carrier lifetimes of…

Materials Science · Physics 2015-09-16 Jingshan Qi , Xiao Li , Qian Niu , Ji Feng

Motivated by a recent experiment (Sanchez-Yamagishi et.al, arXiv:1602.06815) reporting evidence of helical spin-polarized edge states in layer-biased twisted bilayer graphene under a magnetic flux, we study the possibility of stabilising a…

Mesoscale and Nanoscale Physics · Physics 2017-07-13 F. Finocchiaro , F. Guinea , P. San-Jose

Inspired by the profound physical connotations and potential application prospects of the valleytronics, we design a two-dimensional (2D) WS2/h-VN magnetic van der Waals (vdW) heterostructure and study the control of valley degree of…

Computational Physics · Physics 2019-12-04 Congming Ke , Yaping Wu , Weihuang Yang , Zhiming Wu , Chunmiao Zhang , Xu Li , Junyong Kang

In a magnetic field bilayer graphene supports an octet of zero-energy Landau levels with an extra twofold degeneracy in Landau orbitals n=0 and n=1. It is shown that this orbital degeneracy is lifted due to Coulombic quantum fluctuations of…

Mesoscale and Nanoscale Physics · Physics 2012-10-25 K. Shizuya

We consider theoretically the influence of crystalline fields on the electronic structure of graphene placed on a layered material with reduced symmetry and large spin-orbit coupling (SOC). We use a perturbative procedure combined with the…

Mesoscale and Nanoscale Physics · Physics 2018-07-10 Tarik P. Cysne , Aires Ferreira , Tatiana G. Rappoport

We predict that neutral graphene bilayers are pseudospin magnets in which the charge density-contribution from each valley and spin spontaneously shifts to one of the two layers. The band structure of this system is characterized by a…

Strongly Correlated Electrons · Physics 2008-01-18 Hongki Min , Giovanni Borghi , Marco Polini , A. H. MacDonald

Spin waves are promising information carriers which can be used in modern magnonic devices, characterized by higher performance and lower energy consumption than presently used electronic circuits. However, before practical application of…

Mesoscale and Nanoscale Physics · Physics 2019-03-05 M. Mailyan , P. Gruszecki , O. Gorobets , M. Krawczyk

We analyze density-wave and Pomeranchuk orders in twisted bilayer graphene. This compliments our earlier analysis of the pairing instabilities. We assume that near half-filling of either conduction or valence band, the Fermi level is close…

Strongly Correlated Electrons · Physics 2020-09-18 Dmitry V. Chichinadze , Laura Classen , Andrey V. Chubukov

In a graphene Landau level (LL), strong Coulomb interactions and the fourfold spin/valley degeneracy lead to an approximate SU(4) isospin symmetry. At partial filling, exchange interactions can spontaneously break this symmetry, manifesting…

Quantum Hall effects offer a formidable playground for the investigation of quantum transport phenomena. Edge modes can be detected, branched, and mixed by designing a suitable potential landscape in a two-dimensional conducting system…