QDev Seminar by Natalia Ares

Title: Thermodynamics of quantum devices

As we miniaturize devices to reach the quantum regime, the need arises to test the laws of thermodynamics in a new realm, in which fluctuations and quantum effects play a very important role. I will discuss how to explore the thermodynamics of semiconductor devices at nanometer scales, and I will show how we measured the thermodynamic cost of recording the passage of time. We find that the accuracy of our clock and the entropy produced by it are proportional, as predicted both for classical and quantum regimes.

Coupling charge or spin states to mechanical motion might allow us not only to build nanoscale motors but to measure the thermodynamic cost of quantum information processing. Fully suspended carbon nanotube devices allow us to control mechanical, electronic and spin degrees of freedom with high accuracy. Using these devices we find that the coupling of electron transport to the nanotube displacement is ultra-strong. I will discuss how this experimental platform can allow for the study of on-chip quantum energetics.