Nonlinear matter-wave amplification in a 23Na spinor Bose-Einstein condensate
Abstract
An F = 1 , 23Na Bose-Einstein condensate (BEC) in a far off-resonant optical trap has a spinor order parameter for the hyperfine sublevels mF = + 1 , 0 , - 1 . At low magnetic fields pairs of atoms may undergo spin-changing collisions between the | mFA ,mFB > = | 0 , 0 > and | + 1 , - 1 > states. The ground state is a BEC in the mF = 0 state. However, by dressing the F = 1 energy levels with a microwave field off-resonant from the F = 2 state, the sign of the effective quadratic Zeeman energy is reversed and the mF = 0 BEC becomes metastable. Vacuum fluctuations in the initially empty mF = + 1 , - 1 states drive nonlinear amplification of | + 1 , - 1 > atom pairs. When the energy difference is equal to an interaction energy, then the rate of emission of | + 1 , - 1 > pairs is maximal. This realizes a phase-insensitive parametric amplifier for matter waves and is characterized by sub-shot-noise spin correlations between the mF = + 1 and mF = - 1 BECs. We discuss progress in realizing this amplifier in a Na BEC as well as possibilities for building a nonlinear matter-wave interferometer.
- Publication:
-
APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 2011
- Bibcode:
- 2011APS..DMP.K3010W