Quantum pumping and rectification effects in Aharonov-Bohm-Casher ring-dot systems

Romeo, Francesco; Citro, Roberta; Marinaro, M.

doi:10.1103/physrevb.78.245309

Cited by 22 publications

(21 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[35] for a ring, and in Ref. [36] for a ring-dot system, mainly in the context of spin currents. Here we focus on different aspects by starting the analysis with the case of closed rings and determine the energy levels and eigenstates of the relevant Hamiltonian 37,38 .…”

Section: Introductionmentioning

confidence: 99%

Quantum rings with time-dependent spin-orbit coupling: Spintronic Rabi oscillations and conductance properties

et al. 2009

View full text Add to dashboard Cite

The strength of the (Rashba-type) spin-orbit coupling in mesoscopic semiconductor rings can be tuned with external gate voltages. Here we consider the case of a periodically changing spinorbit interaction strength as induced by sinusoidal voltages. In a closed one dimensional quantum ring with weak spin-orbit coupling, Rabi oscillations are shown to appear. We find that the time evolution of initially localized wave packets exhibits a series of collapse and revival phenomena. Partial revivals -that are typical in nonlinear systems -are shown to correspond to superpositions of states localized at different spatial positions along the ring. These "spintronic Schrödinger-cat sates" appear periodically, and similarly to their counterparts in other physical systems, they are found to be sensitive to environment induced disturbances. The time dependent spin transport problem, when leads are attached to the ring, is also solved. We show that the "sideband currents" induced by the oscillating spin-orbit interaction strength can become the dominant output channel, even in the presence of moderate thermal fluctuations and random scattering events. PACS numbers: 85.35.Ds, 03.65.-w * Electronic address: benedict@physx.u-szeged.hu † Electronic address: francois.peeters@ua.ac.be 1 M. König, A. Tschetschetkin, E. M. Hankiewicz, J. Sinova,

show abstract

Section: Introductionmentioning

confidence: 99%

Quantum rings with time-dependent spin-orbit coupling: Spintronic Rabi oscillations and conductance properties

et al. 2009

View full text Add to dashboard Cite

show abstract

“…(12) corresponds to the net amount of heat flow exchanged between the R channel and L channel due to backscattering processes and it does not give any information on the heat which locally enters into each reservoir separately. Using the standard perturbative approach [4,65,72,85] in the tunneling Hamiltonian, the average pumped currents can be calculated. At the lowest order in the tunneling one has the finite temperature currents (here, ν = n,q for particle-number and heat contributions)…”

Section: Average Pumped Currentsmentioning

confidence: 99%

Polarized heat current generated by quantum pumping in two-dimensional topological insulators

et al. 2017

View full text Add to dashboard Cite

We consider transport properties of a two dimensional topological insulator in a double quantum point contact geometry in presence of a time-dependent external field. In the proposed setup an external gate is placed above a single constriction and it couples only with electrons belonging to the top edge. This asymmetric configuration and the presence of an ac signal allow for a quantum pumping mechanism, which, in turn, can generate finite heat and charge current in an unbiased device configuration. A microscopic model for the coupling with the external time-dependent gate potential is developed and the induced finite heat and charge current are investigated. We demonstrate that in the non-interacting case, heat flow is associated with a single spin component, due to the helical nature of the edge states, and therefore a finite and polarized heat current is obtained in this configuration. The presence of e-e interchannel interactions strongly affects the current signal, lowering the degree of polarization of the system. Finally, we also show that separate heat and charge flows can be achieved, varying the amplitude of the external gate.

show abstract

“…[15][16][17][18][19][20][21][22][23][24][25][26][27][28] The quantum pumping, which is highly related to the ratchet effect [29][30][31][32][33] and the photogalvanic effect, [34][35][36] describes the generation of a direct current at zero bias in a spatially asymmetric system under ac fields. 37,38 The quantum pumping of charge and spin currents has been investigated theoretically [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] and observed experimentally in semiconductor quantum dots, [54][55][56] quantum wires, [57][58][59] and also in carbon nanotubes. 15 Recently, the quantum charge and spin pumping in GNRs has also arou...…”

Section: Introductionmentioning

confidence: 99%

Single-parameter quantum charge and spin pumping in armchair graphene nanoribbons

Zhou

2012

Phys. Rev. B

View full text Add to dashboard Cite

We investigate quantum charge and spin pumping in armchair graphene nanoribbons under a single ac gate voltage connected with nonmagnetic/ferromagnetic leads via the nonequilibrium Green's function method. In the case of nonmagnetic leads, where only part of the nanoribbon is subject to an ac gate voltage to break the left-right spatial symmetry, we discover that peaks of the charge pumping current appear at the Fermi energies around the sub-band edges in the ac-field-free region of the nanoribbon. In the case of ferromagnetic leads with the lead magnetizations being antiparallel to break the left-right symmetry, similar peaks appear in the spin pumping current when the Fermi energies are around the edges of the the majority-spin sub-bands in the ferromagnetic leads. All these peaks originate from the pronounced symmetry breaking in the transmissions with energies being around the corresponding sub-band edges. Moreover, we predict a pure spin current in the case of ferromagnetic leads with the whole graphene nanoribbon under an ac gate voltage. The ac-field-strength and ac-field-frequency dependencies of the pumping current are also investigated with the underlying physics revealed.

show abstract

Quantum pumping and rectification effects in Aharonov-Bohm-Casher ring-dot systems

Cited by 22 publications

References 28 publications

Quantum rings with time-dependent spin-orbit coupling: Spintronic Rabi oscillations and conductance properties

Quantum rings with time-dependent spin-orbit coupling: Spintronic Rabi oscillations and conductance properties

Polarized heat current generated by quantum pumping in two-dimensional topological insulators

Single-parameter quantum charge and spin pumping in armchair graphene nanoribbons

Contact Info

Product

Resources

About