Attractive Coulomb interactions in a triple quantum dot

Hong, Chungpyo; Yoo, Gwangsu; Park, Jin‐Hong; Cho, Min-Kyun; Chung, Yunchul; Sim, Hyun Sub; Kim, Dohun; Choi, Hyung Kook; Umansky, V.; Mahalu, D.

doi:10.1103/physrevb.97.241115

Cited by 18 publications

(8 citation statements)

References 18 publications

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“…The Coulomb interaction between electrons is known to be repulsive. However, in a variety of systems with electronic degrees of freedom it has been found that an effective attraction between electrons arises, contrary to naive expectations [23][24][25][26] . It is believed that high-temperature superconductivity can be achieved via an effective attractive interaction mediated by Coulomb repulsion 23 .…”

Section: Introductionmentioning

confidence: 70%

Electron-pairing in the quantum Hall regime due to neutralon exchange

Frigeri,

Rosenow

2020

Preprint

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The behavior of electrons in condensed matter systems is mostly determined by the repulsive Coulomb interaction. However, under special circumstances the Coulomb interaction can be effectively attractive, giving rise to electron pairing in unconventional superconductors and specifically designed mesoscopic setups. In quantum Hall systems electron interactions can play a particularly important role due to the huge degeneracy of Landau levels, leading for instance to the emergence of quasi-particles with fractional charge and anyonic statistics. Quantum Hall Fabry-Pérot (FPI) interferometers have attracted increasing attention due to their ability to probe such exotic physics. In addition, such interferometers are affected by electron interactions themselves in interesting ways. Recently, experimental evidence for electron pairing in a quantum Hall FPI was found (H.K. Choi et al., Nat. Comm 6, 7435 (2015)) . Theoretically describing an FPI in the limit of strong backscattering and under the influence of a screened Coulomb interaction, we compute electron shot noise and indeed find a two-fold enhanced Fano factor for some parameters, indicative of electron pairing. This result is explained in terms of an electron interaction due to exchange of neutral inter-edge plasmons, so-called neutralons.

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Section: Introductionmentioning

confidence: 70%

Electron-pairing in the quantum Hall regime due to neutralon exchange

Frigeri,

Rosenow

2020

Preprint

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“…The excess energy ∆ε = ε 2 s − ε 1 s , required for the electrons to tunnel from S 1 to S 2 is extracted from the reservoir G via Coulomb coupling. Coming to the fabrication feasibility of such a system, due to the recent progress in in nano-fabrication techniques, coupled systems employing multiple (more than two) quantum dots, with and without Coulomb coupling, have already been experimentally realized [39][40][41][42][43][44]. In addition, it has been experimentally demonstrated that spatially and electrically isolated quantum dots may be bridged to obtain strong Coulomb coupling, in addition to excellent thermal insulation [45][46][47][48][49].…”

Section: Proposed Design and Transport Formulationmentioning

confidence: 99%

Realistic non-local refrigeration engine based on Coulomb coupled systems

Barman,

Halder,

Varshney

et al. 2020

Preprint

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Employing Coulomb-coupled systems, we demonstrate a cryogenic non-local refrigeration engine, that circumvents the need for a change in the energy resolved system-to-reservoir coupling, demanded by the recently proposed non-local refrigerators [1][2][3][4][5]. We demonstrate that an intentionally introduced energy difference between the ground states of adjacent tunnel coupled quantum dots, associated with Coulomb coupling, is sufficient to extract heat from a remote target reservoir. Investigating the performance and operating regime using quantum-master-equation (QME) approach, we point out to some crucial aspects of the proposed refrigeration engine. In particular, we demonstrate that the maximum cooling power for the proposed set-up is limited to about 70% of the optimal design. Proceeding further, we point out that to achieve a target reservoir temperature, lower compared to the average temperature of the current path, the applied voltage must be greater than a given threshold voltage VT H , that increases with decrease in the target reservoir temperature. In addition, we demonstrate that the maximum cooling power, as well as the coefficient of performance deteriorates as one approaches a lower target reservoir temperature. The novelty of the proposed refrigeration engine is the integration of fabrication simplicity along with descent cooling power. The idea proposed in this paper may pave the way towards the realization of efficient non-local cryogenic refrigeration systems.

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“…A single-electron transistor (SET) [7] is a phase-coherent conductor that provides a platform for single-electron tunneling, such as the Coulomb blockade [7][8][9][10][11][12][13][14][15] and the spin blockade [16][17][18], and quantum computation with semiconductor quantum dots (QDs) [19][20][21][22][23][24][25][26][27][28]. It comprises a source (electrode), a drain (electrode), two tunnel junctions, and a quantum dot (a conductive island).…”

Section: Introductionmentioning

confidence: 99%

Average Current Through a Single-electron Transistor Under Fluctuations of an Observer’s Frame of Reference

Shin¹

2019

AJPA

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The average current through a single-electron transistor (SET) under fluctuations of an observer's frame of reference (OFR) is reported. To date, the average current through a SET has been studied under the assumption that an OFR remains constant throughout the performance of measurements of the current; thus, it remains an unsolved problem as to what is measured of the current when the OFR is assumed to fluctuate. In this paper, a SET comprising a source, drain, and single channel is considered, where an OFR is assumed to be matched to the electrochemical potential energy of the drain of the SET. The average current through the SET for two types of OFR fluctuation is formulated: periodic-square-wave fluctuation and periodic-sawtooth-wave fluctuation, in time representations. Under these types of fluctuation, the average current exhibits a zero-bias Coulomb peak-the amplitude of which gradually increases with the amplitude of the fluctuation type divided by temperature. The amplitude of the zero-bias Coulomb peak is greater in the case of periodic-square-wave fluctuations. Therefore, the amplitude of the zero-bias Coulomb peak together with a varying of both the energy of the channel and the temperature has the potential to reveal the distribution of fluctuations of an OFR.

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Attractive Coulomb interactions in a triple quantum dot

Cited by 18 publications

References 18 publications

Electron-pairing in the quantum Hall regime due to neutralon exchange

Electron-pairing in the quantum Hall regime due to neutralon exchange

Realistic non-local refrigeration engine based on Coulomb coupled systems

Average Current Through a Single-electron Transistor Under Fluctuations of an Observer’s Frame of Reference

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