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Related papers: Quantum pumping in graphene with a perpendicular m…

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We study a one-dimensional quantum pump composed of two oscillating delta-functional barriers. The linear and non-linear regimes are considered. The harmonic signal applied to any or both barriers causes the stationary current. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 M. M. Mahmoodian , L. S. Braginskii , M. V. Entin

The tunneling effect of two-dimensional Dirac fermions in a constant magnetic field is studied. This can be done by using the continuity equation at some points to determine the corresponding reflexion and transmission coefficients. For…

High Energy Physics - Theory · Physics 2011-04-28 El Bouazzaoui Choubabi , Mohamed El Bouziani , Ahmed Jellal

We present results of tight binding calculations demonstrating existence of degenerate electronic shells of Dirac Fermions in narrow, charge neutral graphene quantum rings. We predict removal of degeneracy with finite magnetic field. We…

Materials Science · Physics 2010-08-30 P. Potasz , A. D. Guclu , P. Hawrylak

A quantum pump device involving magnetic barriers produced by the deposition of ferro magnetic stripes on hetero-structure's is investigated. The device for dc- transport does not provide spin-polarized currents, but in the adiabatic…

Quantum Physics · Physics 2007-05-23 Ronald Benjamin , Colin Benjamin

On the basis of self-consistent Born approximation, we solve the Bethe-Salpeter matrix equations for Cooperon propagator of the Dirac fermions in graphene under the charged impurity scatterings and a weak external magnetic field. In the…

Strongly Correlated Electrons · Physics 2009-10-23 Xin-Zhong Yan , C. S. Ting

This paper is aimed to review and promote the main applications of the methods of Quantum Field Theory to description of quantum effects in graphene. We formulate the effective electromagnetic action following from the Dirac model for the…

High Energy Physics - Theory · Physics 2016-12-22 Ignat V. Fialkovsky , Dmitri V. Vassilevich

We investigate a non-adiabatic parametric quantum pump consists of a nonmagnetic scattering region connected by two ferromagnetic leads. The presence of ferromagnetic leads allows electrons with different spins to experience different…

Condensed Matter · Physics 2009-11-07 Wei Zheng , Junling Wu , Baigeng Wang , Jian Wang , Qingfeng Sun , Hong Guo

In this paper we investigate the relativistic quantum dynamics of a massive excitation in a graphene layer with a wedge disclination in the presence of an uniform magnetic field. We use a Dirac oscillator type coupling to introduce the…

Mesoscale and Nanoscale Physics · Physics 2018-04-04 Jose Amaro Neto , J. R. S. Oliveira , Claudio Furtado , S. Sergeenkov

We discuss the fact that quantum capacitance of graphene-based devices leads to variation of it's charge density under changes of external magnetic field.The charge is conserved, but redistributes to substrate or other graphene sheet. We…

Mesoscale and Nanoscale Physics · Physics 2014-03-28 Sergey Slizovskiy

We demonstrate the operation of a quantum spin pump based on cyclic radio-frequency excitation of a GaAs quantum dot, including the ability to pump pure spin without pumping charge. The device takes advantage of bidirectional mesoscopic…

Mesoscale and Nanoscale Physics · Physics 2012-11-19 Susan K. Watson , R. M. Potok , C. M. Marcus , V. Umansky

A remarkable manifestation of the quantum character of electrons in matter is offered by graphene, a single atomic layer of graphite. Unlike conventional solids where electrons are described with the Schrodinger equation, electronic…

Mesoscale and Nanoscale Physics · Physics 2008-09-16 Z. Q. Li , E. A. Henriksen , Z. Jiang , Z. Hao , M. C. Martin , P. Kim , H. L. Stormer , D. N. Basov

Our previous results on the nonperturbative calculations of the mean current and of the energy-momentum tensor in QED with the T-constant electric field are generalized to arbitrary dimensions. The renormalized mean values are found; the…

High Energy Physics - Theory · Physics 2012-12-24 S. P. Gavrilov , D. M. Gitman , N. Yokomizo

We develop the Floquet scattering theory for quantum mechanical pumping in mesoscopic conductors. The nonequilibrium distribution function, the dc charge and heat currents are investigated at arbitrary pumping amplitude and frequency. For…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 M. Moskalets , M. Buttiker

We study charge and spin pumping in an interacting one-dimensional wire. We show that a spatially periodic potential modulated in space and time acts as a quantum pump inducing a dc-current component at zero bias. The current generated by…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 R. Citro , N. Andrei , Q. Niu

We study spin and charge currents pumped by precessing magnetization of a single ferromagnetic layer within F|I|N or F|I|F (F-ferromagnet; I-insulator; N-normal-metal) multilayers of nanoscale thickness attached to two normal metal…

Mesoscale and Nanoscale Physics · Physics 2009-04-16 Son-Hsien Chen , Ching-Ray Chang , John Q. Xiao , Branislav K. Nikolic

The combination of high frequency vibrations and metallic transport in graphene makes it a unique material for nano-electromechanical devices. In this letter, we show that graphene-based nano-electromechanical devices are extremely well…

Mesoscale and Nanoscale Physics · Physics 2012-03-13 Tony Low , Yongjin Jiang , Mikhail Katsnelson , Francisco Guinea

We theoretically study the Dirac fermion dynamics in a graphene monolayer in the presence of an applied ultrafast laser pulse. The pulse has the duration of a few femtoseconds and the amplitude of ~ 0.1 - 0.5 $\mathrm{V/\AA}$. The waveform…

Mesoscale and Nanoscale Physics · Physics 2019-09-12 S. Azar Oliaei Motlagh , Vadym Apalkov , Mark I. Stockman

We study graphene quantum point contacts (QPC) and imaging of the backscattering of the Fermi level wave function by potential introduced by a scanning probe. We consider both etched single-layer QPCs as well as the ones formed by bilayer…

Mesoscale and Nanoscale Physics · Physics 2017-10-27 Alina Mreńca-Kolasińska , Bartłomiej Szafran

We report a theoretical study of the quantized spin pump in a traditional two-parameter quantum pump device that is based on the helical edge states of a quantum spin Hall insulator. By introducing two time-dependent magnetizations out of…

Mesoscale and Nanoscale Physics · Physics 2018-03-07 Mei-Juan Wang , J. Wang , Jun-Feng Liu

The general covariance of the Dirac equation is exploited in order to explore the curvature effects appearing in the electronic properties of graphene. Two physical situations are then considered: the weak curvature regime, with…

Mesoscale and Nanoscale Physics · Physics 2017-03-29 Pavel Castro-Villarreal , R. Ruiz-Sánchez