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We investigate non-adiabatic electron pumping in graphene generated by laser irradiation with linear polarization parallel or perpendicular to the transport direction. Transport is dominated by the spatially asymmetric excitation of…

Mesoscale and Nanoscale Physics · Physics 2012-10-12 Pablo San-Jose , Elsa Prada , Henning Schomerus , Sigmund Kohler

We study single-parameter quantized charge pumping via a semiconductor quantum dot in high magnetic fields. The quantum dot is defined between two top gates in an AlGaAs/GaAs heterostructure. Application of an oscillating voltage to one of…

Mesoscale and Nanoscale Physics · Physics 2009-01-21 B. Kaestner , Ch. Leicht , V. Kashcheyevs , K. Pierz , U. Siegner , H. W. Schumacher

We investigate adiabatic quantum pumping of chiral Majorana states in a system composed of two Mach--Zehnder type interferometers coupled via a quantum point contact. The pumped current is generated by periodic modulation of the phases…

Mesoscale and Nanoscale Physics · Physics 2014-01-22 M. Alos-Palop , Rakesh P. Tiwari , M. Blaauboer

We investigate spin and charge current through a quantum dot pumped by a time-varying magnetic field. Using the density matrix method, quantum rate equations for the electronic occupation numbers in the quantum dot are obtained and solved…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Zhao Yang Zeng , Hong Li , Baowen Li

Single electron pumps are set to revolutionize electrical metrology by enabling the ampere to be re-defined in terms of the elementary charge of an electron. Pumps based on lithographically-fixed tunnel barriers in mesoscopic metallic…

We study the spin current injected by spin pumping into single layer graphene and the two-dimensional electron gas (2DEG) with ferromagnetic contacts using scattering theory. The spin currents pumped into graphene are very distinct from…

Mesoscale and Nanoscale Physics · Physics 2016-11-30 Takuya Inoue , Gerrit E. W. Bauer , Kentaro Nomura

We study magneto--optical properties of monolayer graphene by means of quantum field theory methods in the framework of the Dirac model. We reveal a good agreement between the Dirac model and a recent experiment on giant Faraday rotation in…

Mesoscale and Nanoscale Physics · Physics 2012-11-30 I. V. Fialkovsky , D. V. Vassilevich

In this work, pumped currents of the adiabatically-driven double-barrier structure based on the pseudospin-1 Dirac-Weyl fermions are studied. As a result of the three-band dispersion and hence the unique properties of pseudospin-1…

Mesoscale and Nanoscale Physics · Physics 2020-09-14 Xiaomei Chen , Rui Zhu

We present a proposal for an adiabatic quantum pump based on a graphene monolayer patterned by electrostatic gates and operated in the low-energy Dirac regime. The setup under investigation works in the presence of inhomogeneous spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2012-09-20 Dario Bercioux , Daniel F. Urban , Francesco Romeo , Roberta Citro

We investigate pure spin pumping in graphene by imposing a ferromagnet (F) with rotating magnetization on top of it. Using the generalized scattering approach for adiabatic spin pumping, we obtain the spin current pumped through magnetic…

Mesoscale and Nanoscale Physics · Physics 2015-07-29 Mojtaba A. Rahimi , Ali G. Moghaddam

Electrostatic confinement of charge carriers in graphene is governed by Klein tunneling, a relativistic quantum process in which particle-hole transmutation leads to unusual anisotropic transmission at pn junction boundaries. Reflection and…

We study the physics of Dirac fermions in a gapped graphene monolayer containing two Coulomb impurities. For the case of equal impurity charges, we discuss the ground-state energy using the linear combination of atomic orbitals (LCAO)…

Mesoscale and Nanoscale Physics · Physics 2014-08-12 D. Klöpfer , A. De Martino , D. Matrasulov , R. Egger

We show that graphene-based quantum pumps can tap into evanescent modes, which penetrate deeply into the device as a consequence of Klein tunneling. The evanescent modes dominate pumping at the Dirac point, and give rise to a universal…

Mesoscale and Nanoscale Physics · Physics 2009-12-15 Elsa Prada , Pablo San-Jose , Henning Schomerus

Transmission of Dirac fermions through a chip of graphene under the effect of magnetic field and a time vibrating double barrier with frequency $w$ is investigated. Quantum interference within the oscillating barrier has an important effect…

Mesoscale and Nanoscale Physics · Physics 2015-03-05 Miloud Mekkaoui , El Bouâzzaoui Choubabi , Ahmed Jellal , Hocine Bahlouli

In this paper the results of numerical simulation of monolayer graphene in external magnetic field are presented. The numerical simulation is performed in the effective lattice field theory with noncompact $3 + 1$-dimensional Abelian…

High Energy Physics - Lattice · Physics 2014-06-13 D. L. Boyda , V. V. Braguta , S. N. Valgushev , M. I. Polikarpov , M. V. Ulybyshev

The charge transported when a quantum pump is adiabatically driven by time-dependent external forces in presence of dissipation is given by the line integral of a pumping field $\mathbf{F}$. We give a general expression of $\mathbf{F}$ in…

Quantum Physics · Physics 2014-09-29 Juzar Thingna , Peter Hänggi , Rosario Fazio , Michele Campisi

A two-dimensional periodic array of scatterers has been introduced to a single layer of graphene in the presence of an external magnetic field perpendicular to the graphene layer. The eigenvalue equation for such a system has been solved…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 Godfrey Gumbs , Andrii Iurov , Danhong Huang , Paula Fekete , Liubov Zhemchuzhna

We present a theoretical study of quantum charge pumping with a single ac gate applied to graphene nanoribbons and carbon nanotubes operating with low resistance contacts. By combining Floquet theory with Green's function formalism, we show…

Mesoscale and Nanoscale Physics · Physics 2011-09-01 L. E. F. Foa Torres , H. L. Calvo , C. G. Rocha , G. Cuniberti

Quantum pumping holds great potential for future applications in micro- and nanotechnology. Its main feature, dissipationless charge transport, is theoretically possible via several different mechanisms. However, since no unambiguous…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Markku Jaaskelainen , Frank Corvino , Christopher P. Search , Vassilios Fessatidis

We calculate the energy spectrum and eigenstates of a graphene sheet which contains a circular deformation. Using time-independent perturbation theory with the ratio of the height and width of the deformation as the small parameter, we find…

Mesoscale and Nanoscale Physics · Physics 2012-02-28 G. M. M. Wakker , Rakesh P. Tiwari , M. Blaauboer