Jeudi 12 décembre 2002
A atomic-gas Bose-Einstein Condensate, placed in the periodic light-shift potential of an optical standing way, exhibits many features that are similar to the familiar problem of electrons moving in the periodic potential of a solid-state crystal lattice.
Differences include the distance scale of the lattice (100s of nanometers compared to a few Ångstroms) and the fact that the BEC represents a wavefunction whose coherence extends over the entire lattice, with what is essentially a single quasi momentum.
Recent experiments at NIST-Gaithersburg explore the behavior of a BEC in an optical lattice and interpret the sometimes surprising results using traditional band theory.