Magnetopumping current in graphene Corbino pump

Abstract

We study conductance and adiabatic pumped charge and spin currents in a graphene quantum pump with Corbino geometry in the presence of an applied perpendicular magnetic field. The pump is driven by the periodic and out of phase modulations of the magnetic field and an electrostatic potential applied to the ring area of the pump. We show that the Zeeman splitting, despite of its smallness, can suppress the conductance oscillations at the zero doping and in a threshold value for the flux piercing the ring area which depends on the inner lead radius and thus on the flux penetrating in it. Moreover, it generates a considerable spin conductance at infinitesimal nonzero doping and at the magnetic flux, that charge conductance starts to suppress. We find that the pumped charge and spin currents increase by the magnetic field with small oscillations until they start to suppress due to the effect of the nonzero doping and the Zeeman splitting. In graphene Corbino pumps with small inner leads the Zeeman splitting shows its effect in a large value of the magnetic field and thus we can get a considerable pumped charge and spin currents at the enough small magnetic fields.Comment: 14 pages, 13 figure

Adiabatic quantum pumping in buckled graphene nanoribbon driven by a kink

“…The idea of quantum pumping, i.e., transferring the charge between electronic reservoirs by periodic modulation of the device connecting these reservoirs [1], has been widely discussed in the context of graphene nanostructures [2,3,4,5,6,7,8]. Since early works, elaborating the gate-driven pumping mechanism in graphene [2] and bilayer graphene [3], it becomes clear that the transport via evanescent modes may significantly enhance the effectiveness of graphene-based pumps compared to other quantum pumps.…”

“…Since early works, elaborating the gate-driven pumping mechanism in graphene [2] and bilayer graphene [3], it becomes clear that the transport via evanescent modes may significantly enhance the effectiveness of graphene-based pumps compared to other quantum pumps. Other pumping mechanisms considered involves laser irradiation [4], strain fields [5], tunable magnetic barriers [6], Landau quantization [7], or even sliding the Moiré pattern in twisted bilayer graphene [8].…”

Graphene disk in a solenoid magnetic potential: Aharonov-Bohm effect without a two-slit-like setup

“…Quantum transport through the Corbino disk in graphene has been addressed both theoretically [1][2][3][4][5][6][7] and experimentally [8][9][10][11] by numerous authors, as the egde-free geometry allows one to probe the mesoscopic aspects of graphene, such as transport via evanescent waves [12], even in nanometerscale devices. At zero magnetic field, conductance of ultraclean ballistic disks as a fuction of the carrier concentration [10] shows good agreement with the basic mode-matching analysis of Ref.…”

Adiabatic pumping driven by moving kink and quantum standard ampere in buckled graphene nanoribbon

“…In attempt to improve electromechanical characteristics of such devices, one need to address fundamental issues concerning the structure of effective Hamiltonian at nanoscale, including tight-binding parameters [3], elastic coefficients [4,5], and electron phononcoupling [6]. Numerous works have addressed the idea of quantum pumping in graphene nanostructures [7][8][9][10][11][12][13][14][15], employing various physical mechanisms. These include gatedriven pumping [7,8], laser light [9], strain-induced fields [10], tunable magnetoresistance [11], quantum Hall states [12], but also electromechanical effects accompanying sliding Moiré patterns in twisted bilayer [13,14], or (most recently) moving kink in buckled graphene nanoribbon [15].…”

“…Numerous works have addressed the idea of quantum pumping in graphene nanostructures [7][8][9][10][11][12][13][14][15], employing various physical mechanisms. These include gatedriven pumping [7,8], laser light [9], strain-induced fields [10], tunable magnetoresistance [11], quantum Hall states [12], but also electromechanical effects accompanying sliding Moiré patterns in twisted bilayer [13,14], or (most recently) moving kink in buckled graphene nanoribbon [15].…”