A two-atom electron pump

Roche, B.; Riwar, Roman-Pascal; Voisin, B.; Dupont-Ferrier, Eva; Wacquez, R.; Vinet, M.; Sanquer, M.; Splettstoesser, Janine; Jehl, X.

doi:10.1038/ncomms2544

Cited by 93 publications

(105 citation statements)

References 31 publications

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“…The DQD is periodically driven at frequency ω g =2π by applying oscillating voltages V L ðtÞ and V R ðtÞ to the gates. The relative amplitude and phase of these voltages are set such that [28] ϵðtÞ ¼ ϵ 0 þ eV ac sinðω g tÞ:…”

Section: Driven Dqd Gain Mediummentioning

confidence: 99%

Double Quantum Dot Floquet Gain Medium

et al. 2016

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Strongly driving a two-level quantum system with light leads to a ladder of Floquet states separated by the photon energy. Nanoscale quantum devices allow the interplay of confined electrons, phonons, and photons to be studied under strong driving conditions. Here, we show that a single electron in a periodically driven double quantum dot functions as a "Floquet gain medium," where population imbalances in the double quantum dot Floquet quasienergy levels lead to an intricate pattern of gain and loss features in the cavity response. We further measure a large intracavity photon number n c in the absence of a cavity drive field, due to equilibration in the Floquet picture. Our device operates in the absence of a dc current-one and the same electron is repeatedly driven to the excited state to generate population inversion. These results pave the way to future studies of nonclassical light and thermalization of driven quantum systems.

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Section: Driven Dqd Gain Mediummentioning

confidence: 99%

Double Quantum Dot Floquet Gain Medium

et al. 2016

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“…This device ideally generates a quantized output current, I P = nef , where n is an integer and f is the frequency of an external periodic drive. Several enabling technologies have already been developed including metal/oxide tunnel barrier devices 6,7 , normal-metal/superconductor turnstiles 8,9 , graphene double quantum dots 10 , donor-based pumps [11][12][13] , silicon-based quantum dot pumps [14][15][16][17][18] and GaAs-based quantum dot pumps [19][20][21][22][23][24][25][26][27] . To date, the latter scheme provides the lowest uncertainty of 1.2 parts per million (ppm) yielding current in excess of 150 pA 27 .…”

mentioning

confidence: 99%

An Accurate Single-Electron Pump Based on a Highly Tunable Silicon Quantum Dot

et al. 2014

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Nanoscale single-electron pumps can be used to generate accurate currents, and can potentially serve to realize a new standard of electrical current based on elementary charge. Here, we use a silicon-based quantum dot with tunable tunnel barriers as an accurate source of quantized current. The charge transfer accuracy of our pump can be dramatically enhanced by controlling the electrostatic confinement of the dot using purposely engineered gate electrodes. Improvements in the operational robustness, as well as suppression of non-adiabatic transitions that reduce pumping accuracy, are achieved via small adjustments of the gate voltages. We can produce an output current in excess of 80 pA with experimentally determined relative uncertainty below 50 parts per million.As early as one and a half centuries ago, J. C. Maxwell envisaged the need for a system of standards based on phenomena at the atomic scale and directly related to invariant constants of nature. 1 However, Maxwell could not anticipate that, in order to harness the behaviour of the world at the nanometer scale, a completely new physical interpretation was needed, namely, quantum mechanics. At first, the laws of quantum mechanics seemed to reveal fundamental limits to the accuracy of physical measurements. Concepts like the Heisenberg uncertainty principle, which imposes intrinsic fluctuations on the values of non-commuting observables, and the wavefunction collapse, responsible for the randomization of a system configuration after performing a measurement, appeared to be at odds with the requirement of deterministic consistency that is paramount for metrological purposes. Nevertheless, quantum-based systems are today acknowledged as the most stable and reliable metrological tools, as they can be strongly intertwined with fundamental constants. Exquisitely quantum-mechanical phenomena such as the ac Josephson effect 2 and the quantum Hall effect 3 have paved the way towards new and more reliable reference standards for the units of voltage and resistance, respectively.Major efforts are currently ongoing to re-define the unit of electrical current, the ampere (A), in terms of the elementary charge, e, by means of quantum technologies 4,5 . A practical implementation of this standard may be the electron pump, a device in which a quantum phenomenon, namely tunnelling, and classical Coulomb repulsion, are combined to control the transfer of an integer number of elementary charges. This device ideally generates a quantized output current, I P = nef , where n is an integer and f is the frequency of an external periodic drive. Several enabling technologies have already been developed including metal/oxide tunnel barrier devices 6,7 , normal-metal/superconductor turnstiles 8,9 , graphene double quantum dots 10 , donor-based pumps 11-13 , silicon-based quantum dot pumps 14-18 and GaAs-based quantum dot pumps [19][20][21][22][23][24][25][26][27] . To date, the latter scheme provides the lowest uncertainty of 1.2 parts per million (ppm) yielding current in excess o...

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“…Hence the circuits based on fixed tunnel barriers arXiv:1412.7150v2 [cond-mat.mes-hall] 29 Jul 2015 naturally lend themselves to the realization of adiabatic pumping schemes where the number of confined charges is kept close to equilibrium (defined by the leads and the environment) during most parts of the operation cycle. A notable example of a successful implementation of the adiabatic approach is the development of single-electrontunneling pumps consisting of a series of small metallic islands [15] or, recently, atomic donor states [16] coupled by fixed tunnel barriers. Using this principle Keller et al [17] achieved an uncertainty of 15 × 10 −9 with f up to a few MHz determined by electron counting.…”

Section: Introductionmentioning

confidence: 99%

Non-adiabatic quantized charge pumping with tunable-barrier quantum dots: a review of current progress

2015

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Precise manipulation of individual charge carriers in nanoelectronic circuits underpins practical applications of their most basic quantum property -the universality and invariance of the elementary charge. A charge pump generates a net current from periodic external modulation of parameters controlling a nanostructure connected to source and drain leads; in the regime of quantized pumping the current varies in steps of qef as function of control parameters, where qe is the electron charge and f is the frequency of modulation. In recent years, robust and accurate quantized charge pumps have been developed based on semiconductor quantum dots with tunable tunnel barriers. These devices allow modulation of charge exchange rates between the dot and the leads over many orders of magnitude and enable trapping of a precise number of electrons far away from equilibrium with the leads. The corresponding non-adiabatic pumping protocols focus on understanding of separate parts of the pumping cycle associated with charge loading, capture and release. In this report we review realizations, models and metrology applications of quantized charge pumps based on tunable-barrier quantum dots.

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A two-atom electron pump

Cited by 93 publications

References 31 publications

Double Quantum Dot Floquet Gain Medium

Double Quantum Dot Floquet Gain Medium

An Accurate Single-Electron Pump Based on a Highly Tunable Silicon Quantum Dot

Non-adiabatic quantized charge pumping with tunable-barrier quantum dots: a review of current progress

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