Spin-dependent thermoelectric properties of a Kondo-correlated quantum dot with Rashba spin–orbit coupling

Karwacki, Łukasz; Trocha, Piotr; Barnaś, J.

doi:10.1088/0953-8984/25/50/505305

Cited by 19 publications

(26 citation statements)

References 82 publications

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“…The interplay between strong correlations and various interference effects significantly modifies transport properties of systems based on double quantum dots [42][43][44][45][46][47][48][49][50]. Particularly, the interplay of Dicke and Kondo effects has been predicted to greatly increase transport characteristics in quantum dot systems [23,51,52] and is likely to increase thermoelectric power of the system [50,[53][54][55].…”

Section: Introductionmentioning

confidence: 99%

“…These effects were already confirmed in a range of materials such as magnetic metals, magnetic semiconductors, or magnetic insulators. However, it was shown theoretically that the intrinsic properties of quantum dot systems that influence charge-dependent effects could affect spin-dependent thermoelectric effects as well [28,52,[61][62][63][64][65][66]. One of the particularly characteristic features is the strong dependence of spin thermopower on magnetic polarization of the adjacent leads.…”

Section: Introductionmentioning

confidence: 99%

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Spin-dependent thermoelectric effects in a strongly correlated double quantum dot

Karwacki¹,

Trocha²

2016

Phys. Rev. B

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We investigate spin-dependent thermoelectric transport through a system of two coupled quantum dots attached to reservoirs of spin-polarized electrons. Generally, we focus on the strongly correlated regime of transport. To this end, a slave-boson method for finite U is employed. Our main goal is to show that, apart from complex low-temperature physics, such a basic multilevel system provides a possibility to examine various quantum interference effects, with particular emphasis put on the influence of such phenomena on thermoelectric transport. Apart from the influence of interference effects on spin-degenerate charge transport, we show how spin-dependent transport, induced by ferromagnetic leads, can be modified as well. Finally, we also consider the case where the spin-relaxation time in the ferromagnetic leads is relatively long, which leads to the so-called spin thermoelectric effects.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Spin-dependent thermoelectric effects in a strongly correlated double quantum dot

Karwacki¹,

Trocha²

2016

Phys. Rev. B

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“…The effect of spin-orbit coupling of the Rashba type is treated in Ref. [41]. Finally, we briefly mention exciting topics where thermoelectrics in Kondo artificial impurities play a significant role: relaxation dynamics [42], orbital degrees of freedom [43,44], universal ac thermopower [45], hybrid devices connected to ferromagnetic and superconducting leads [46], assisted hopping [47] and different configurations such as parallel [48] or side coupled double QDs [49].…”

Section: Introductionmentioning

confidence: 99%

Fate of the spin- 12 Kondo effect in the presence of temperature gradients

Sierra¹,

López²,

Sánchez³

2017

Phys. Rev. B

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We consider a strongly interacting quantum dot connected to two leads held at quite different temperatures. Our aim is to study the behavior of the Kondo effect in the presence of large thermal biases. We use three different approaches, namely, a perturbation formalism based on the Kondo Hamiltonian, a slave-boson mean-field theory for the Anderson model at large charging energies and a truncated equation-of-motion approach beyond the Hartree-Fock approximation. The two former formalisms yield a suppression of the Kondo peak for thermal gradients above the Kondo temperature, showing a remarkably good agreement despite their different ranges of validity. The third technique allows us to analyze the full density of states within a wide range of energies. Additionally, we have investigated the quantum transport properties (electric current and thermocurrent) beyond linear response. In the voltage-driven case, we reproduce the split differential conductance due to the presence of different electrochemical potentials. In the temperature-driven case, we observe a strongly nonlinear thermocurrent as a function of the applied thermal gradient. Depending on the parameters, we can find nontrivial zeros in the electric current for finite values of the temperature bias. Importantly, these thermocurrent zeros yield direct access to the system's characteristic energy scales (Kondo temperature and charging energy).

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“…For a spin-degenerate quantum dot (QD) the conductance experiences an enhancement for low temperatures due to the Kondo effect [13,14]. The thermopower of the single and multiple quantum dots in the presence of the Kondo effect was examined both theoretically [6,[15][16][17][18][19][20][21][22][23][24][25][26][27][28] and experimentally [29]. On the other hand, in the case of two degenerate levels with equal spin, at degeneracy, conductance can be suppressed due to electron correlation and interference effects [30][31][32][33][34][35].…”

Section: Introductionmentioning

confidence: 99%

Thermopower signatures and spectroscopy of the canyon of conductance suppression

2016

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Thermopower signatures and spectroscopy of the canyon of conductance suppressionKirsanskas, Gediminas; Hammarberg, S.; Karlström, O.; Wacker, Andreas General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Interference effects in quantum dots between different transport channels can lead to a strong suppression of conductance, which cuts like a canyon through the common conductance plot [Phys. Rev. Lett. 104, 186804 (2010)]. In the present work we consider the thermoelectric transport properties of the canyon of conductance suppression using the second-order von Neumann approach. We observe a characteristic signal for the zeros of the thermopower. This demonstrates that thermoelectric measurements are an interesting complimentary tool to study complex phenomena for transport through confined systems.

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Spin-dependent thermoelectric properties of a Kondo-correlated quantum dot with Rashba spin–orbit coupling

Cited by 19 publications

References 82 publications

Spin-dependent thermoelectric effects in a strongly correlated double quantum dot

Spin-dependent thermoelectric effects in a strongly correlated double quantum dot

Fate of the spin- 12 Kondo effect in the presence of temperature gradients

Thermopower signatures and spectroscopy of the canyon of conductance suppression

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