Single Cooper-pair pumping in the adiabatic limit and beyond

Gasparinetti, Simone; Solinas, Paolo; Yoon, Y.; Pekola, Jukka P.

doi:10.1103/physrevb.86.060502

Cited by 19 publications

(21 citation statements)

References 36 publications

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“…Although for G T ( 1=R K the rates of these more complex multistep electron ''cotunneling'' processes are small in comparison with the rates of the single-step sequential electron tunneling, they are frequently important either because they provide the only energetically allowed transport mechanism or because they limit the accuracy of control of the basic sequential single-electron transitions. The simplest example of the cotunneling is the current leakage in the SET in the CB regime (Averin and Odintsov, 1989;Geerligs, Averin, and Mooij, 1990), when the bias voltage V is smaller than the CB threshold and any single-step electron transfer that changes the charge en on the transistor island by AEe (see Fig. 5) would increase the charging energy (3) and is suppressed.…”

Section: B Sequential Single-electron Tunnelingmentioning

confidence: 99%

“…Furthermore, since the charge of a single Cooper pair is 2e, single-Cooper-pair pumps yield twice the current compared with single-electron pumps operated at the same frequency. Despite these advantages, the lowest uncertainties in the achieved Cooper-pair current is at the percent level (Vartiainen et al, 2007;Gasparinetti et al, 2012). One reason for this is the low impedance of the device, rendering it susceptible to current noise.…”

Section: E Superconducting Charge Pumpsmentioning

confidence: 99%

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Single-electron current sources: Toward a refined definition of the ampere

et al. 2013

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The control of electrons at the level of the elementary charge e was demonstrated experimentally already in the 1980s. Ever since, the production of an electrical current ef, or its integer multiple, at a drive frequency f has been a focus of research for metrological purposes. This review discusses the generic physical phenomena and technical constraints that influence single-electron charge transport and presents a broad variety of proposed realizations. Some of them have already proven experimentally to nearly fulfill the demanding needs, in terms of transfer errors and transfer rate, of quantum metrology of electrical quantities, whereas some others are currently ''just'' wild ideas, still often potentially competitive if technical constraints can be lifted. The important issues of readout of singleelectron events and potential error correction schemes based on them are also discussed. Finally, an account is given of the status of single-electron current sources in the bigger framework of electric quantum standards and of the future international SI system of units, and applications and uses of single-electron devices outside the metrological context are briefly discussed.

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Section: B Sequential Single-electron Tunnelingmentioning

confidence: 99%

Section: E Superconducting Charge Pumpsmentioning

confidence: 99%

Single-electron current sources: Toward a refined definition of the ampere

et al. 2013

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“…Both Landau-Zener transitions 29,38,46 and noise 32,35,37,47 may excite the system causing the transferred charge to drop. In the original model, the parameter cycle was designed such that the two lowest states were well separated from the rest of the eigenspectrum.…”

Section: B Numerical Analysismentioning

confidence: 99%

“…36,37 Both methods also have the potential for describing pumping when the driving is nonadiabatic, a regime recently studied experimentally. 38 Furthermore, a current induced directly by the environment has been shown to emerge for certain types of noise operators 39 leading to a development of a conservation law for all operator currents in open quantum systems. 40 To date, all considerations of the sluice have assumed an exact phase bias.…”

Section: Introductionmentioning

confidence: 99%

Quantum effect of inductance on geometric Cooper-pair transport

Salmilehto

Möttönen

2012

Phys. Rev. B

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We introduce a model for a flux-assisted Cooper-pair pump, the sluice, which is used to study geometric charge transport. Our model allows for a nonvanishing loop inductance going beyond the usual treatment with an exact phase bias. We derive the device Hamiltonian and current operators for different elements of the system and calculate the pumped charge carried by the ground state in the adiabatic limit. We show that extending the model beyond the exact phase bias, has a weak but potentially non-negligible effect on the charge transport. This effect is observed to depend on the external flux bias. The adiabatic energy level and eigenstate structures are studied and the unusual features are explained. Finally, we discuss the requirements of adiabaticity.Comment: 13 pages, 6 figures, final versio

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“…The quasienergy gap of the sluice can thus be tuned by changing the superconducting phase bias while performing exactly the same pulse sequence. This makes the sluice an excellent candidate to verify our theoretical predictions through a direct measurement of the pumped charge Q p [32,33].…”

mentioning

confidence: 99%

Environment-Governed Dynamics in Driven Quantum Systems

et al. 2013

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We show that the dynamics of a driven quantum system weakly coupled to the environment can exhibit two distinct regimes. While the relaxation basis is usually determined by the system þ drive Hamiltonian (system-governed dynamics), we find that under certain conditions it is determined by specific features of the environment, such as, the form of the coupling operator (environment-governed dynamics). We provide an effective coupling parameter describing the transition between the two regimes and discuss how to observe the transition in a superconducting charge pump. Introduction.-Understanding how quantum systems interact with the environment [1] is of paramount importance in quantum information science. While unveiling how the classical world emerges from the quantum one [2], it can also lead to a better protection against decoherence effects on the way towards the realization of a quantum computer [3].A standard approach to the dynamics of open quantum systems boils the problem down to the measurement of decoherence rates, distinguishing between coherence loss, or dephasing, and relaxation. While this approach has successfully described a variety of quantum systems, it only offers a limited insight into the dynamics of decoherence. A promising line of work developed in the last decade exploits the possibility of coupling the system to an engineered reservoir [4][5][6][7][8][9][10][11][12].As new and more accurate ways are found of harnessing the dynamic evolution of quantum systems, it becomes increasingly important to understand how the interaction with the environment is affected by a time-dependent modulation of the system parameters. Indeed, the study of dissipation in driven quantum systems is a longestablished topic [13] that keeps finding new applications to quantum pumping [14][15][16], quantum computation [17,18], and possibly even biological systems [19,20].In this Letter, we consider a periodically driven quantum system in the presence of a weakly coupled environment. We show that under certain conditions decoherence takes place in a preferred basis determined by specific features of the environment, such as, the type of noise, rather than of the system. We label this unusual regime as environmentgoverned dynamics (EGD), as opposed to the more familiar system-governed dynamics (SGD). We introduce an effective coupling parameter that presides over the transition between SGD and EGD. This parameter can be tuned by changing the properties of the drive. Our analysis is general and applies to optical and solid-state systems alike.

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Single Cooper-pair pumping in the adiabatic limit and beyond

Cited by 19 publications

References 36 publications

Single-electron current sources: Toward a refined definition of the ampere

Single-electron current sources: Toward a refined definition of the ampere

Quantum effect of inductance on geometric Cooper-pair transport

Environment-Governed Dynamics in Driven Quantum Systems

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