Pulsed Quantum Tunneling with Matter Waves

TL;DR

This paper explores macroscopic quantum tunneling of Bose-Einstein condensates under gravity and barriers, showing quasi-periodic tunneling and coherent atomic pulse generation, with improved modeling via an effective 1D NPSE.

Contribution

It introduces a more accurate 1D NPSE derived from the 3D Gross-Pitaevskii equation for cigar-shaped condensates, enhancing modeling precision.

Findings

Quantum tunneling can be quasi-periodic.

Coherent Bose condensed atomic pulses can be generated.

NPSE provides more accurate results than other 1D models.

Abstract

In this report we investigate the macroscopic quantum tunneling of a Bose condensate falling under gravity and scattering on a Gaussian barrier that could model a mirror of far-detuned sheet of light. We analyze the effect of the inter-atomic interaction and that of a transverse confining potential. We show that the quantum tunneling can be quasi-periodic and in this way one could generate coherent Bose condensed atomic pulses. In the second part of the report, we discuss an effective 1D time-dependent non-polynomial nonlinear Schrodinger equation (NPSE), which describes cigar-shaped condensates. NPSE is obtained from the 3D Gross-Pitaevskii equation by using a variational approach. We find that NPSE gives much more accurate results than all other effective 1D equations recently proposed.