We treat the nonequilibrium motion of a single-impurity atom in a low-temperature single-species Fermi sea, interacting via a contact interaction. In the nonequilibrium regime, the impurity does a superdiffusive geometric random walk where the typical distance traveled grows with time as ∼td /(d +1 ) for the d-dimensional system with d2. For nonzero temperature T, this crosses over to diffusive motion at long times with diffusivity D∼T -(d -1 )/2. These results apply also to a nonzero concentration of impurity atoms as long as they remain dilute and nondegenerate.
|Original language||English (US)|
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|State||Published - Apr 6 2012|
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics