We explore coherent information transfer between ultra-slow and stopped
laser light pulses [1]
and atomic BECs. In [1], pulses of a probe laser were stopped, stored,
and later revived by
switching off and on a coupling laser. We show that this switching
process can occur coherently
on time scales much faster than the adiabatic time scale for electromagnetically
induced
transparency [2]. When this is done in a BEC, the light pulses create
spatial features in the
atomic fields and we find the ensuing two-component dynamics gives
rise to interference
fringes and solitons. Switching the coupling field back on writes the
dynamics onto probe pulses,
allowing the condensate to process the optical information. Extensions
to quantum information are
anticipated.
[1] C. Liu, Z. Dutton, C.H. Behroozi, and L.V. Hau, Nature 409, 490
(2001);
D.F. Phillips, et al., Phys. Rev. Lett. 86, 783 (2001).
[2] S.E. Harris, Physics Today 50, 36 (1997).