Charge pumping in quantum wires

Faizabadi, Edris; Ebrahimi, Farshad

doi:10.1088/0953-8984/16/10/011

Cited by 11 publications

(12 citation statements)

References 17 publications

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“…The escaping or leaking of electrons from the dot increases with increasing coupling strength which also reduces the time that electrons relax to the reservoirs. Therefore, one would expect the performance of pumping to be suppressed by the increased coupling strength due to the opening of the dot, [16][17][18][19] or the dephasing due to the inelastic scattering from a third fictitious voltage probe. 20) (2) If the current is a result of any circuitry effect (for example, classical dependence of the resistance on the applied electric fields or cross talk between the electric signals), I p would increase monotonically with increasing dot resistance regardless of the mode number N, and I p ½N ¼ ð0; 0Þ should be greater than I p ½N ¼ ð1; 1Þ.…”

Section: Resultsmentioning

confidence: 99%

Time Dependent Electric Fields Generated DC Currents in a Large Gate-Defined Open Dot

Liu¹,

Umansky

Hsu³

2010

Jpn. J. Appl. Phys.

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We present the study of DC currents of an open dot generated from two time dependent electric fields in the absence of external bias. Two electrical setups were applied. In one configuration, two fast oscillating voltages were applied on two side gates; in the other, one of the oscillating biases was directly applied to the source lead. The DC current as a function of frequency, coupling strength, and magnetic field was investigated. The current is sinusoidally dependent with the phase shift and bilinearly dependent with the excitation voltage for both configurations. However, the current as a function of frequency, coupling strength, and magnetic fields behaves differently in these two setups. The results indicate that the currents generated in different setups originate from different mechanisms, and moreover, not from any classical circuitry effect.

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Section: Resultsmentioning

confidence: 99%

Time Dependent Electric Fields Generated DC Currents in a Large Gate-Defined Open Dot

Liu¹,

Umansky

Hsu³

2010

Jpn. J. Appl. Phys.

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“…for QD or double-QD (double-atom) systems [2,5,[9][10][11]. Also onedimensional quantum structures in the presence of periodic potentials applied to two sites were proposed as charge pumps [12][13][14][15][16]. For more complex systems adiabatic quantum pumps have been studied as well, e.g.…”

Section: Introductionmentioning

confidence: 99%

Mono-parametric charge pumping through a quantum dot coupled with energy-gapped leads

Kwapiński

Taranko

2015

Eur. Phys. J. B

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Abstract. We present a proposal for a single-parametric electron pump composed of a quantum dot between two unbiased leads with energy-gapped electron density of states (DOS). The model tight-binding Hamiltonian and the evolution operator technique are used in the calculations. The quantum dot is driven by the external harmonic field which leads to the pumping current flowing from the left or right electrode depending on the system parameters. We show that the net pumping current appears in the system if (i) there are at least two sideband states: one of them lying below and the second lying above the Fermi energy; (ii) the left and right lead DOS in the vicinity of these sideband states are different. Moreover, the energy-gapped structure of DOS is visible on the average quantum dot charge and the pumped current curves as well as on the transconductance characteristics. Thus mono-parametric pumping provides useful information about the system parameters, in particular about the lead DOS structure.

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“…In this case the phase difference in the ac signal (between both QD sites) is crucial for electron pumping. In one-dimensional systems an oscillating potential (harmonic, pulsed or delta-like) applied to two sites of a wire [23][24][25][26] as well as the train impulse [11] can generate the net electron or spin currents.…”

Section: Introductionmentioning

confidence: 99%

Phase-dependent electron transport through a quantum wire on a surface

Kwapiński

2012

J. Phys.: Condens. Matter

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Electron transport through a quantum wire in the presence of external periodic energy-level modulations with different on-site phases is studied within the time evolution operator method for a tight-binding Hamiltonian. It is found that in the presence of spatial symmetry of the system and no source-drain and static gate voltages the pumping current can be generated. Moreover, for a wire which is tunnel-coupled to the underlying substrate, the current flowing through an unbiased wire does not fade away but increases with the wire-surface coupling. For randomly chosen phases at every wire site two regimes of the phase-averaged current are found which are related to small and high wire density of states.

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Charge pumping in quantum wires

Cited by 11 publications

References 17 publications

Time Dependent Electric Fields Generated DC Currents in a Large Gate-Defined Open Dot

Time Dependent Electric Fields Generated DC Currents in a Large Gate-Defined Open Dot

Mono-parametric charge pumping through a quantum dot coupled with energy-gapped leads

Phase-dependent electron transport through a quantum wire on a surface

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