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Related papers: A Quantum Singlet Pump

200 papers

We consider quantum charge pumping of electrons across a superconducting double barrier structure in the adiabatic limit. The superconducting barriers are assumed to be reflection-less so that an incident electron on the barrier can either…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Arijit Saha , Sourin Das

Adiabatically pumped charge, carried by non-interacting electrons through a quantum dot in a turnstile geometry, is studied as function of the strength of the two modulating potentials (related to the conductances of the two point-contacts…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 O. Entin-Wohlman , Amnon Aharony

We study charge and spin transport through an interacting quantum wire, caused by backscattering off an effective impurity potential with a periodic time-dependence. The adiabatic regime of this pump for charge and spin is shown to depend…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Prashant Sharma , Claudio Chamon

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

The Schroedinger equation with a potential periodically varying in time is used to model adiabatic quantum pumps. The systems considered may be either infinitely extended and gapped or finite and connected to gapless leads. Correspondingly,…

Mathematical Physics · Physics 2015-05-13 G. Braeunlich , G. M. Graf , G. Ortelli

In the adiabatic and weak-modulation quantum pump, net electron flow is driven from one reservoir to the other by absorbing or emitting an energy quantum $\hbar \omega $ from or to the reservoirs. In our approach, high-order dependence of…

Mesoscale and Nanoscale Physics · Physics 2009-11-09 Rui Zhu

We study a mesoscopic circuit of two quantized current sources, realized by non-adiabatic single- electron pumps connected in series with a small micron-sized island in between. We find that quantum transport through the second pump can be…

In a mesoscopic system, under zero bias voltage, a finite charge is transferred by quantum adiabatic pumping by adiabatically and periodically changing two or more control parameters. We obtained expressions for the pumped charge for a ring…

Mesoscale and Nanoscale Physics · Physics 2016-09-22 Masahiko Taguchi , Satoshi Nakajima , Toshihiro Kubo , Yasuhiro Tokura

Quantum pumping through mesoscopic quantum dots is known to be enhanced by resonant transmission. The pumped charge is close to an integer number of electrons when the pumping contour surrounds a resonance, but the transmission remains…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Vyacheslavs Kashcheyevs , Amnon Aharony , Ora Entin-Wohlman

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

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

In quantum metrology, semiconductor single-electron pumps are used to generate accurate electric currents with the ultimate goal of implementing the emerging quantum standard of the ampere. Pumps based on electrostatically defined tunable…

Mesoscale and Nanoscale Physics · Physics 2018-07-12 A. Rossi , J. Klochan , J. Timoshenko , F. E. Hudson , M. Möttönen , S. Rogge , A. S. Dzurak , V. Kashcheyevs , G. C. Tettamanzi

Motivated by experimental realizations of integer quantized charge pumping in one-dimensional superlattices~[Nat. Phys. 12, 350 (2016); Nat. Phys. 12, 296 (2016)], we generalize and propose the adiabatic pumping of a fractionalized charge…

Strongly Correlated Electrons · Physics 2016-12-19 Tian-Sheng Zeng , W. Zhu , D. N. Sheng

The adiabatic topological pumping is proposed by periodically modulating a semiconductor nanowire double-quantum-dot chain. We demonstrate that the quantized charge transport can be achieved by a nontrivial modulation of the quantum-dot…

Mesoscale and Nanoscale Physics · Physics 2021-11-23 Zhi-Hai Liu , H. Q. Xu

We study the quantum spin pumping of an antiferromagnetic spin-1/2 chain with competing exchange interactions. We show that spatially periodic potential modulated in space and time acts as a quantum spin pump. In our model system, an…

Strongly Correlated Electrons · Physics 2009-11-13 Sujit Sarkar , C. D. Hu

Full insight into the dynamics of a coupled quantum system depends on the ability to follow the effect of a local excitation in real-time. Here, we trace the coherent evolution of a pair of coupled atomic spins by means of scanning…

The charge current pumped adiabatically through a deformable quantum dot is studied within the Green's function approach. Differently from the non-deformable case, the current shows an undefined parity with respect to the pumping phase…

Mesoscale and Nanoscale Physics · Physics 2010-10-05 F. Romeo , R. Citro

We develop a method to calculate electronic transport properties through a mesoscopic scattering region in the presence of a series of time-periodic potentials. Using the method, the quantum charge pumping driven by time-periodic potentials…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Shi-Liang Zhu , Z. D. Wang

We review recent progresses in the theoretical description of correlation and quantum fluctuation phenomena in charge transport through single molecules, quantum dots, and quantum wires. A variety of physical phenomena is addressed,…

Mesoscale and Nanoscale Physics · Physics 2010-06-28 S. Andergassen , V. Meden , H. Schoeller , J. Splettstoesser , M. R. Wegewijs

Adiabatic quantum pumping in noninteracting, phase coherent quantum dots is elegantly described by Brouwer's formula. Interactions within the dot, while suppressing phase coherence, make Brouwer's formalism inapplicable. In this paper, we…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Davide Fioretto , Alessandro Silva