Abstract
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 $$^{85}$$
85
Rb atomic sources with the current experimentally-achievable momentum width of $$0.02 \hbar k_0$$
0.02
ħ
k
0
[$$k_0 = 2\pi /(780~\text {nm})$$
k
0
=
2
π
/
(
780
nm
)
], we show that reasonably high contrast Fabry–Perot resonant transmission peaks can be observed using (a) non-interacting BECs, (b) interacting BECs of $$5 \times 10^4$$
5
×
10
4
atoms with s-wave scattering lengths $$a_s=\pm 0.1a_0$$
a
s
=
±
0.1
a
0
($$a_0$$
a
0
is the Bohr radius), and (c) interacting BECs of $$10^3$$
10
3
atoms with $$a_s=\pm 1.0a_0$$
a
s
=
±
1.0
a
0
. Our theoretical investigation impacts any future experimental realization of an atomic Fabry–Perot interferometer with an ultracold atomic source.