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Previous Michelson Postdoctoral Prize Lectureships

May 11, 2000 , Colloquium

Keith Schwab, NSA, University of Maryland

Measurement of the Universal Quantum of Thermal Conductance

We have performed experiments to probe directly the thermal conductance of suspended nanostructures with lateral dimensions ~100nm. It has been recently predicted that at low temperatures, thermal conductance in such a structure approaches a universal value of $\pi^2 k_B^2 \over
       3h$ for each massless, ballistic 1D channel, independent of material characteristics. We have developed ultra-sensitive, low dissipation dc-SQUID-based noise thermometry, and extreme isolation from the electronic environment in order to perform this measurement at temperatures <100mK. We will report our very recent successful measurements of this universal quantum of thermal conductance and the implications for single photon and possibly single phonon calorimetry.
Host: CWRU Physics Department