Single-electron spectroscopy in a coupled triple-dot system: Role of interdot electron-electron interactions

Lee, S. D.; Park, K. S.; Park, J. W.; Choi, Jihun; Yang, Sen; Yoo, Kyung Hwa; Kim, J.; Park, S. I.; Kim, K. T.

doi:10.1103/physrevb.62.r7735

Cited by 20 publications

(10 citation statements)

References 15 publications

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“…As such, the effective control of larger parameter spaces as well as the calibration of larger samples seem like insurmountable obstacles. What has been lacking, thus, is an efficient and scalable control paradigm for Hamiltonian engineering that extends to the collective Fermi-Hubbard parameter regimes well beyond those required for qubit operation [29,30,31,32] and described merely by (local) spin excitations.…”

Section: Introductionmentioning

confidence: 99%

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Hensgens

Fujita

Janssen

et al. 2017

Nature

326

329

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Interacting fermions on a lattice can develop strong quantum correlations, which lie at the heart of the classical intractability of many exotic phases of matter [1, 2, 3, 4]. Seminal efforts are underway in the control of artificial quantum systems, that can be made to emulate the underlying Fermi-Hubbard models [5, 6, 7, 8,9,10,11]. Electrostatically confined conduction band electrons define interacting quantum coherent spin and charge degrees of freedom that allow all-electrical pure-state initialisation and readily adhere to an engineerable Fermi-Hubbard Hamiltonian [12,13,14,15,16,17,18,19,20,21,22,23]. Until now, however, the substantial electrostatic disorder inherent to solid state has made attempts at emulating Fermi-Hubbard physics on solid-state platforms few and far between [24,25]. Here, we show that for gate-defined quantum dots, this disorder can be suppressed in a controlled manner. Novel insights and a newly developed semi-automated and scalable toolbox allow us to homogeneously and independently dial in the electron filling and nearest-neighbour tunnel coupling. Bringing these ideas and tools to fruition, we realize the first detailed characterization of the collective Coulomb blockade transition [26], which is the finite-size analogue of the interaction-driven Mott metal-to-insulator transition [1]. As automation and device fabrication of semiconductor quantum dots continue to improve, the ideas presented here show how quantum dots can be used to investigate the physics of ever more complex many-body states.

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Section: Introductionmentioning

confidence: 99%

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Hensgens

Fujita

Janssen

et al. 2017

Nature

326

329

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“…Surprsingly, electronic transport through the triple sites has been less investigated in the past both theoretically and experimentally [28]. In this subsection, we study the detailed dependence of the number and profile of transmission peaks, on the parameters of such a structure.…”

Section: Triple Sitesmentioning

confidence: 99%

“…A coupled triple site structure is expected to contain richer physics than a coupled double site system, since it permits more interesting arrangement of the energy levels in each site and the competition between inter-site couplings. Surprsingly, electronic transport through the triple sites has been less investigated in the past both theoretically and experimentally [28]. In this subsection, we study the detailed dependence of the number and profile of transmission peaks, on the parameters of such a structure.…”

Section: Triple Sitesmentioning

confidence: 99%

Coherent transmission through a one-dimensional lattice

et al. 2004

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Based on the Keldysh nonequilibrium Green function (NGF) technique, a general formula for the current and transmission coefficient through a one dimensional lattice is derived without the consideration of electron-electron interactions. We obtain an analytical condition for perfect resonant transmission when the levels of sites are aligned, which depends on the parity of the number of sites. Localization-delocalization transition in a generic one dimensional disordered lattice is also analyzed, depending on the correlation among the hopping parameters and the strength of the coupling to reservoirs. The dependence of the number and lineshape of resonant transmission and linear conductance peaks on the structure parameters of the lattice is also given in several site cases.

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“…[18], we take U ∼ ∆ rather than U ≫ ∆, so that the Andreev reflection (AR) process [19,20] and the Coulomb blockade (CB) effect may "combine" with each other (U is the constant of the intra-dot Coulomb interaction, ∆ is the gap of the superconducting electrodes, and the choice of U ∼ ∆ is physically reasonable). In the calculation, we take into account not only intra-dot but also inter-dot Coulomb interactions, both of which are found to be important in the fitting of the experimental data [4].…”

mentioning

confidence: 99%

“…The electron-electron interactions play an essential role in the transport properties of CQD, due to that the electrons are added to the molecule one by one, and the conductance exhibits Coulomb blockade oscillations. Such appealing system has attracted a lot of experimental and theoretical attentions, such as the observations of Coulomb blockade in double or triple quantum dots [1][2][3][4]; the measurement of microwave spectroscopy of a quantum dot molecule and the comparison with the time dependent theory [5][6][7]; the analysis of the additional spectra of CQD in the magnetic field by using single electron capacitance spectroscopy [8]; the investigations of electronic correlations and Kondo effect in CQD by two impurity Anderson model [9,10], and much more.…”

mentioning

confidence: 99%

Probing spin states of coupled quantum dots by a dc Josephson current

2002

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We propose an idea for probing spin states of two coupled quantum dots (CQD), by the dc Josephson current flowing through them. This theory requires weak coupling between CQD and electrodes, but allows arbitrary inter-dot tunnel coupling, intra-and inter-dot Coulomb interactions. We find that the Coulomb blockade peaks exhibit a non-monotonous dependence on the Zeeman splitting of CQD, which can be understood in terms of the Andreev bound states. More importantly, the supercurrent in the Coulomb blockade valleys may provide the information of the spin states of CQD: for CQD with total electron number N=1,3 (odd), the supercurrent will reverse its sign if CQD becomes a magnetic molecule; for CQD with N=2 (even), the supercurrent will decrease sharply around the transition between the spin singlet and triplet ground states of CQD.

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Single-electron spectroscopy in a coupled triple-dot system: Role of interdot electron-electron interactions

Cited by 20 publications

References 15 publications

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Quantum simulation of a Fermi–Hubbard model using a semiconductor quantum dot array

Coherent transmission through a one-dimensional lattice

Probing spin states of coupled quantum dots by a dc Josephson current

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