Dynamic non-destructive detection of Bose-Einstein condensates and atom lasers

E. Carlo Samson, Anshuman Vinit, Chandra Raman

Eva Bookjans, Chandra Raman

Chad Fertig, Mary Locke, Ken Kansky

S. Martellucci, M. Inguscio, Alain Aspect +1 more

Ebubechukwu O. Ilo-Okeke, Tim Byrnes

We investigate a non-destructive homodyne measurement of atomic condensates using off-resonant optical laser beam that interacts with atomic Bose-Einstein condensate (BEC). The interaction between laser beam and the atomic BEC creates entangled states of atom and light that are destroyed in a homodyne detection of light. The destruction of the entangled states causes back-action on the atomic states. We derive expression for the measurement operator on the atomic states due to the photon measurement. We characterize the back-action by calculating quantities such as the Q-function and observe the variation of the measured state with the strength of the light-BEC interaction.

C. Figl, Laurent Longchambon, Matthew Jeppesen +4 more

We present the first detector that is capable of recording high-bandwidth atom number density measurements of a Bose-Einstein condensate, with a readout of the data in real time. It is based on a shot-noise-limited unbalanced Mach-Zehnder interferometer designed for a minimally destructive measurement of the atom column density of a Bose-Einstein condensate. The shot-noise limit is reached by phase modulating the laser in one arm and phase locking the interferometer with a second-color laser. The detector is characterized, and its sensitivity for a fractional change in the column density of a Bose-Einstein condensate is calculated. With this detection system it may be possible to implement feedback to stabilize a Bose-Einstein condensate or an atom laser.