Dresden 2009 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 13: Focussed Session: Superconducting Quantum Circuits
TT 13.4: Topical Talk
Dienstag, 24. März 2009, 11:15–11:45, HSZ 03
Experiments on the quantum of heat conductance — •Jukka Pekola1, Matthias Meschke1, Andrey Timofeev1, Wiebke Guichard2, Meri Helle1, and Mikko Möttönen1,3 — 1Low Temperature Laboratory, Helsinki University of Technology, Finland — 2Institut Neel, C.N.R.S., Grenoble, France — 3Department of Applied Physics, Helsinki University of Technology, Finland
The fundamental limit to transmit heat via a single channel is governed by the quantum of thermal conductance. This has been demonstrated in experiments on both phonons [1,2] and electrons [3]: here we present two experiments [4,5] on this phenomenon based on electromagnetic coupling (photons). In the first experiment tunable electric impedance is used to modulate the radiated heat between two resistors at different temperatures in a superconducting micro-circuit. In the second experiment we demonstrate electronic refrigeration at the quantum limit using superconductor-normal metal tunnel junctions. We discuss the limits of classical and quantum heat exchange in an electrical circuit.
[1] K. Schwab, E. A. Henriksen, J. M. Worlock, M. L. Roukes, Nature 404, 974 (2000).
[2] C. S. Yung, D. R. Schmidt, A. N. Cleland, Appl. Phys. Lett. 81, 31 (2002).
[3] O. Chiatti, J. T. Nicholls, Y. Y. Proskuryakov, N. Lumpkin, I. Farrer, D. A. Ritchie, Phys. Rev. Lett. 97, 056601 (2006).
[4] M. Meschke, W. Guichard, J. P. Pekola, Nature 444, 187 (2006).
[5] A.V. Timofeev, M. Helle, M. Meschke, M. Möttönen, J.P. Pekola, submitted (2008).