Regensburg 2007 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 13: Poster 1

HL 13.54: Poster

Montag, 26. März 2007, 15:00–17:30, Poster A

Quantum Thermal Conductance of Electrons in a One-Dimensional Wire — •O. Chiatti¹, J. T. Nicholls², Y. Y. Proskuryakov³, N. Lumpkin⁴, I. Farrer⁴, and D. A. Ritchie⁴ — ¹Forschungszentrum Dresden-Rossendorf, Hochfeld-Magnetlabor Dresden (HLD), 01328 Dresden, Germany — ²Department of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK — ³Department of Physics, Durham University, Durham DH1 3LE, UK — ⁴Department of Physics, Cavendish Laboratory, Cambridge CB3 0HE, UK

An electron thermometer is used to measure the temperature rise of approximately 2 × 10⁵ electrons in a two-dimensional box, due to heat flow into the box through a ballistic one-dimensional (1D) constriction. Using a simple model we deduce the thermal conductance κ(V_g) of the 1D constriction, which we compare to its electrical conductance characteristics. For the first four 1D subbands the heat carried by the electrons passing through the wire is proportional to its electrical conductance G(V_g). In the vicinity of the 0.7 structure this proportionality breaks down, and a plateau at the thermal-conductance quantum, π²k_B²T/3h, is observed. [Phys. Rev. Lett. 97, 056601 (2006)]