Nano heat engines
Post date: Jan 23, 2012 4:05:03 PM
Updated: Published here.
Will they solve the energy crisis? Perhaps, but either way, I am very excited about the physics here. It combines symmetry breaking, rectification, the second law of thermodynamics, and something called Brillouin's paradox which is related to Maxwell's demon.
Rectification of thermal fluctuations in a chaotic cavity heat engine
Björn Sothmann, Rafael Sánchez, Andrew N. Jordan, Markus Büttiker
The geometry below describes a nanometer-scale electrical conductor fabricated in a semiconductor hetero-structure.
The idea is that electrons entering the upper (cold) cavity will gain energy from the lower (hot) cavity via the coupling capacitance C. The conductances of the contacts are greater at higher energies, so the electron is more likely to leave the lead. The contacts are asymmetric, so you get a directed electrical current, even though no external voltage is applied.
See the paper for the whole story.