Quantum-diffractive background gas collisions in atom-trap heating and loss

Abstract

We derive a simple formula for the heating rate that arises from quantum-diffractive background gas collisions in atom traps. This result appears to explain the residual heating rates reported for recent experiments with a Cs vapor-loaded, far-detuned optical trap at $\ensuremath{\simeq}{10}^{\ensuremath{-}9}$ Torr [Phys. Rev. Lett. 81, 5768 (1998)]. Diffractive collisions may determine the minimum heating rates achievable in shallow all-optical or magnetic atom traps operating at low temperature and high density.