Removal of excitations of Bose-Einstein condensates by space- and time-modulated potentials

Abstract

We propose that periodically in space-and time-modulated potentials (dynamic lattices) can efficiently remove the excited (the high-energy and large momentum) components of the trapped Bose-Einstein condensates (BECs) and, consequently, can result in efficient cleaning of the BECs. We prove the idea by numerically solving the mean-field models (the Schrödinger equation for noninteracting condensates and the Gross-Pitaevskii equation for interacting condensates of repulsive atoms), and we evaluate parameters and conditions for the efficient removal of excitations.

Woodpile photonic crystal for beam collimation

“…The variation of refractive index contrast, of longitudinal and transverse periods of the crystal is drastically affecting intensity distribution of the field as summarized in the Fig.2.a.b.c. In fact, in these figures we see the signatures of spatial beam filtering as part of distribution has dips which correspond to the diffracted components from the spatial spectrum (see more in [3] for light, in [24] for acoustics and in [25] Bose condensate waves). What is important here, are the angular distribution of the phase of transmitted wave components Fig.2.d.e.f.…”

Femtosecond direct laser writing of photonic spatial filters in soda–lime glass

“…PhC length was limited by the maximal working distance of the objective, i. e. ≈300 µm, that for the given geometry corresponds to the highest possible number of periods of N max = 50. A lower NA <1 objective lens, as used in [16,19], might be more suitable for generating higher length modifications Δl with a potentially higher amplitude of the refractive index modulation Δn max , but results in spherical aberrations. Also, large period number PhCs are difficult to realize as mechanical stress accumulated throughout the structure can induce failures, leading to crack formation or even shattering.…”

“…Such kind of filtering has been recently demonstrated experimentally in different 3D configurations using PhCs with a square symmetry in transverse space [15,16], as well as photonic structures with axisymmetric rings [17,18]. The gapless filtering has been recently proposed also to clean atomic ensembles on Bose-Einstein condensates [19].…”

Faraday and Resonant Waves in Dipolar Cigar-Shaped Bose-Einstein Condensates

“…Therefore, these two phenomena can be easily distinguished, not only by comparing their frequencies, but also the corresponding onset times. We note that resonant behavior can appear not only due to the modulation of the interaction strength or the trapping potential, but also due to its spatial modulation [31][32][33][34][35][36][37][38][39][40].…”