%0 Journal Article %@ 0031-9007 %A Chiatti, O %A Nicholls, JT %A Proskuryakov, YY %A Lumpkin, N %A Farrer, I %A Ritchie, DA %D 2006 %F discovery:20434 %I AMERICAN PHYSICAL SOC %J Physical Review Letters %K POINT CONTACTS, GAS, QUANTIZATION, TRANSPORT %N 5 %P 056601-1 %T Quantum thermal conductance of electrons in a one-dimensional wire %U https://discovery.ucl.ac.uk/id/eprint/20434/ %V 97 %X We use an electron thermometer to measure the temperature rise of approximately 2x10(5) 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 kappa(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 quantum of thermal conductance pi(2)k(B)(2)T/3h is observed. %Z © 2006 The American Physical Society