Fig. 2: Fourier spectroscopy.
From: Topological features without a lattice in Rashba spin-orbit coupled atoms
a The initial thermally occupied xyz states \(\left|j,{\bf{k}}\right\rangle\) lead to the displayed quasimomentum distribution. The black dots represent k = 0 for each of the xyz states which is mapped to non-zero q, the red dot represents q = 0 and the blue star indicates the quasimomentum (q1, q2) = (−0.55, −0.18)kL. We used non-condensed atoms with a broad momentum distribution (T ≈ 180 nK and T/Tc ≈ 1.1) and performed our experiments starting separately in each of the xyz states, sampling a large range of quasimomentum states. b We applied the Raman lasers for a variable time tp: a Rabi-type atomic interferometer analogous to a three-port beam splitter. c Probabilities as a function of quasimomentum for a fixed Raman pulse time tp = 420 μs d Dynamics of the final populations of the x (blue), y (red) and z (green) states with quasimomentum (q1, q2) = (−0.55, −0.18)kL (red star in panels a and c) after initializing the system in the \(\left|z\right\rangle\) state.
