DOI: 10.1209/epl/i2001-00559-8


Europhys. Lett., 56 (4) , pp. 576-582 (2001)

Thermoelectric effects in Kondo-correlated quantum dots

D. Boese¹ and R. Fazio<sup>2

1</sup>  Institut für Theoretische Festkörperphysik, Universität Karlsruhe D-76128 Karlsruhe, Germany and Forschungszentrum Karlsruhe, Institut für Nanotechnologie D-76021 Karlsruhe, Germany
²  NEST-INFM & Dipartimento Metodologie Fisiche e Chimiche (DMFCI) Università di Catania - Viale A. Doria 6, I-95125 Catania, Italy

dboese@tfp.physik.uni-karlsruhe.de

(Received 14 May 2001; accepted in final form 24 August 2001)

Abstract
In this letter we study thermoelectric effects in ultra-small quantum dots. We study the behaviour of the thermopower, Peltier coefficient and thermal conductance both in the sequential tunneling regime and in the regime where Kondo correlations develop. Both cases of linear response and non-equilibrium induced by strong temperature gradients are considered. The thermopower is a very sensitive tool to detect Kondo correlations. It changes sign as a function of both temperature and temperature gradient. We also discuss violations of the Wiedemann-Franz law.

PACS
72.20.Pa - Thermoelectric and thermomagnetic effects.
72.15.Qm - Scattering mechanisms and Kondo effect.
73.23.Hk - Coulomb blockade; single-electron tunneling.


© EDP Sciences 2001