Capacitively coupled double quantum dot system in the Kondo regime

Ferreira, Irisnei; Orellana, P. A.; Martins, G. B.; Souza, F. M.; Vernek, E.

doi:10.1103/physrevb.84.205320

Cited by 22 publications

(19 citation statements)

References 60 publications

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“…A telling example is the interplay of Kondo physics and quantum interference in "side-coupled" or "hanging-dot" configurations, [11][12][13][14][15][16][17][18][19] leading to a variety of interesting "Fano-Kondo" effects. 20 A rather unexpected situation arises when a small, strongly interacting "dot 1" is connected to external leads via a large "dot 2" that is tuned to have a single-particle level in resonance with the common Fermi energy of the leads.…”

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confidence: 99%

Spin-polarized conductance in double quantum dots: Interplay of Kondo, Zeeman, and interference effects

et al. 2013

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We study the effect of a magnetic field in the Kondo regime of a double-quantum-dot system consisting of a strongly correlated dot (the "side dot") coupled to a second, noninteracting dot that also connects two external leads. We show, using the numerical renormalization group, that application of an in-plane magnetic field sets up a subtle interplay between electronic interference, Kondo physics, and Zeeman splitting with nontrivial consequences for spectral and transport properties. The value of the side-dot spectral function at the Fermi level exhibits a nonuniversal field dependence that can be understood using a form of the Friedel sum rule that appropriately accounts for the presence of an energy-and spin-dependent hybridization function. The applied field also accentuates the exchange-mediated interdot coupling, which dominates the ground state at intermediate fields leading to the formation of antiparallel magnetic moments on the dots. By tuning gate voltages and the magnetic field, one can achieve complete spin polarization of the linear conductance between the leads, raising the prospect of applications of the device as a highly tunable spin filter. The system's low-energy properties are qualitatively unchanged by the presence of weak on-site Coulomb repulsion within the second dot.

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Spin-polarized conductance in double quantum dots: Interplay of Kondo, Zeeman, and interference effects

et al. 2013

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“…in agreement with Refs. [6,10]. For finite Γ S1 , Γ S2 and Γ SX the situation is more complicated, because there are four states to be eliminated.…”

Section: Application To the Model Under Considerationmentioning

confidence: 99%

“…Local exchange between the spin of a quantum dot (QD) and the spin of conduction band electrons gives rise to the Kondo effect [2,5]. Direct exchange arriving with an additional side-coupled QD may destroy it or lead to the two-stage Kondo screening [4,[6][7][8][9][10]. In a geometry where the two QDs contact the same lead, conduction band electrons mediate the RKKY exchange [11][12][13].…”

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confidence: 99%

Nonlocal pairing as a source of spin exchange and Kondo screening

Wójcik¹,

Weymann²

2019

Phys. Rev. B

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We show that the Kondo screening in a correlated double quantum dot structure may be caused solely by the proximity of a superconductor, which induces nonlocal pairing by Andreev reflection processes. This leads to an effective exchange interaction, which we estimate perturbatively and corroborate the analytical predictions by the numerical renormalization group calculations, using an effective model for the superconductor-proximized nanostructure. We determine the dependence of the relevant Kondo temperature on the coupling to superconductor and predict a characteristic modification of conventional low-temperature transport behavior, which can be used to experimentally distinguish this phenomenon from other Kondo effects. The occurrence of nonlocal pairing exchange does not depend on details of the proposed setup, therefore it can be also of relevance for the bulk materials, such as heavy-fermion compounds. arXiv:1809.06415v2 [cond-mat.str-el]

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“…This configuration is often referred to as a e-mail: kpwojcik@amu.edu.pl 1 See also references cited in references [11][12][13][14]. T-shaped DQD.…”

Section: Introductionmentioning

confidence: 99%

“…In the past few years, transport properties of double quantum dots (DQDs), from which only one is coupled directly to the leads, and the second is side-coupled to the first one, were addressed in a number of papers [11][12][13][14] 1 . This configuration is often referred to as a e-mail: kpwojcik@amu.edu.pl 1 See also references cited in references [11][12][13][14].…”

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confidence: 99%

Ferromagnets-induced splitting of molecular states of T-shaped double quantum dots

Wójcik

2015

Eur. Phys. J. B

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Abstract. The exchange field for molecular states of double quantum dot, induced by two ferromagnets coupled to the device in T-shaped configuration, is defined and calculated. It is found, that in the regime of strong coupling between quantum dots, the dependence of the exchange field on this coupling becomes nontrivial. In particular, it changes the sign a few times to eventually vanish in the limit of infinite inter-dot coupling. The excitation energies of double quantum dot are calculated and the results used to predict the conditions for suppression of the two-stage Kondo effect in the considered nanostructure.

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Capacitively coupled double quantum dot system in the Kondo regime

Cited by 22 publications

References 60 publications

Spin-polarized conductance in double quantum dots: Interplay of Kondo, Zeeman, and interference effects

Spin-polarized conductance in double quantum dots: Interplay of Kondo, Zeeman, and interference effects

Nonlocal pairing as a source of spin exchange and Kondo screening

Ferromagnets-induced splitting of molecular states of T-shaped double quantum dots

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