An atomic Fabry–Perot interferometer using a pulsed interacting Bose–Einstein condensate

We numerically demonstrate atomic Fabry–Perot resonances for a pulsed interacting Bose–Einstein condensate (BEC) source transmitting through double Gaussian barriers. These resonances are observable for an experimentally-feasible parameter choice, which we determined using a previously-developed analytical model for a plane matter-wave incident on a double rectangular barrier system. Through numerical simulations using the non-polynomial Schödinger equation—an effective one-dimensional Gross–Pitaevskii equation—we investigate the effect of atom number, scattering length, and BEC momentum width on the resonant transmission peaks. For ⁸⁵Rb atomic sources with the current experimentally-achievable momentum width of 0.02 ħk [k0=2π/(780nm)], we show that reasonably high contrast Fabry–Perot resonant transmission peaks can be observed using (a) non-interacting BECs, (b) interacting BECs of 5 × 10 ⁴ atoms with s-wave scattering lengths a_s= ± 0.1 a (a is the Bohr radius), and (c) interacting BECs of 10 ³ atoms with a_s= ± 1.0 a. Our theoretical investigation impacts any future experimental realization of an atomic Fabry–Perot interferometer with an ultracold atomic source.