Accessing thermodynamic quantities at the nanoscale*

The development of quantum devices that can be controlled with great speed and precision has presented us with the opportunity to probe thermodynamics processes at the nanoscale. We were able to estimate the thermodynamic cost of timekeeping by measuring the motion of a nanometer-thick membrane excited by electrical noise. 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 to measure the thermodynamic cost of quantum information processing. With fully-suspended carbon nanotube devices, we find that the coupling of electron transport to the nanotube displacement is ultra-strong. This interaction is allowing us to study engines in which quantum effects are present.