Berlin 2015 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 89: Transport: Quantum Dots, Quantum Wires, Point Contacts 1 (jointly with HL)
TT 89.8: Talk
Thursday, March 19, 2015, 12:45–13:00, A 053
Heat current as a tool to study quantum dot decay rates — •Jens Schulenborg1, Roman Saptsov2,3, Janine Splettstoesser1, and Maarten R. Wegewijs2,3,4 — 1Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, Göteborg, Sweden — 2Peter Grünberg Institut, Forschungszentrum Jülich, 52425 Jülich, Germany — 3JARA - Future Information Technologies, Germany — 4Institut für Theorie der Statistischen Physik, RWTH Aachen University, Germany
Over the past years, potential applications in nanoelectronics, metrology and quantum information sparked great interest in studying the dynamics of time-dependently driven quantum dots. Recently, we investigated the decay rates of an interacting single-level quantum dot, weakly tunnel coupled to an electronic reservoir and brought out of equilibrium by a step pulse[1,2]. In particular, the fermion-parity rate[1] was found to be an additional time scale, besides the spin- and charge decay rate, of which the value is fundamentally restricted[2].
This work shows that the time-dependent heat current emitted from the dot gives new insights into the physics described by the fermion-parity rate. Using a master equation for the dot coupled to an electrode, we extract the decay rates and determine how they influence the decay of charge- and heat current. We find that, while the fermion-parity rate does not at all enter the charge current, it is the dominant time scale for the dissipation of interaction energy carried by the heat current.
[1] L. D. Contreras-Pulido et al., Phys. Rev. B 85, 075301 (2012).
[2] R. Saptsov et al., Phys. Rev. B 90, 045407 (2014).