Cold-Atom Thermoelectrics

摘要

Thermoelectric devices can convert temperature differences into electric power, or cool materials by passing currents. On page 713 of this issue, Bran-tut et al. (V) demonstrate this kind of coupling between particle and heat currents in a laser-controlled cloud of lithium atoms. The precise control of such cold-atom systems allows for an accurate tuning of the thermoelectric effects that is usually not possible in solid-state systems. Such model systems will provide a testing ground for ideas aimed at improving thermoelectric devices. Passing a current through an electric conductor heats it up due to its inherent resistance to the current. Under suitable conditions, a small current can also create a temperature difference across a contact between two conductors, so that one part cools down and the other heats up. This Peltier effect (2) is typically weak but is used in electricity-powered portable coolers.