Ultrafast coherent control of spinor Bose-Einstein condensates using stimulated Raman adiabatic passage

Abstract

We propose the use of stimulated Raman adiabatic passage (STIRAP) to offer a fast high fidelity method of performing SU(2) rotations on spinor Bose Einstein condensates (BEC). Past demonstrations of BEC optical control suffer from difficulties arising from collective enhancement of spontaneous emission and inefficient two-photon transitions originating from selection rules. We present here a novel scheme which allows for arbitrary coherent rotations of two-component BECs while overcoming these issues. Numerical tests of the method show that for BECs of 87 Rb with up to 10 4 atoms and gate times of 1 µs, decoherence due to spontaneous emission can be suppressed to negligible values.

Macroscopic quantum information processing using spin coherent states

“…[31], it was shown that by a suitable choice of parameters it is possible to obtain gates in the range of ∼ MHz, which still exceed the gate speeds based on microwave pulses. An alternative method based on the stimulated Raman adiabatic passage (STIRAP) potentially offers a far more superior approach, as it involves dark states not involving the excited state at all [48]. By eliminating the excited state contribution this greatly suppresses the dephasing due to spontaneous emission, which is one of the main drawbacks of using optical methods to control BECs.…”

Coherent control of nonlinear mode transitions in Bose–Einstein condensates

“…For instance, the control of the onset of self-trapping of a condensate in a periodically modulated double well has been demonstrated [15]. Also, SU(2) rotations on spinor condensates has been coherently controlled by stimulated Raman adiabatic passage [16]. In addition, there have been several experimental and theoretical successful implementations of quantum optimal control algorithms for BEC [17][18][19][20][21][22][23][24].…”

“…Thus, upon changing the relative phase of these amplitudes, it is possible to modify the nal yield. This interference between quantum transition amplitudes is the underlying principle of coherent control [15][16][17][18][19][20][21][22]. Here, we consider the role of the relative phase of the modulations on the transitions between nonlinear modes.…”