Energy barrier for collapse in a pair of tunnel-coupled condensates with the scattering lengths of opposite signs

TL;DR

This paper predicts an energy barrier preventing collapse in a system of two tunnel-coupled quasi-2D condensates with opposite scattering lengths, revealing stable ground states with more atoms in the repulsive condensate.

Contribution

It introduces the concept of an energy barrier for collapse in coupled condensates with opposite scattering lengths, combining numerical and analytical methods to identify stable ground states.

Findings

Existence of a stable ground state with more atoms in the repulsive condensate.

Energy barrier arises from tunneling dynamics between condensates.

Analytical and numerical determination of the domain of stable states.

Abstract

We predict the existence of an energy barrier for collapse in a system of two tunnel-coupled repulsive and attractive quasi two-dimensional condensates trapped in a double-well potential. The ground state in such a system can have a lower energy than that of the collapsing state. We find such ground states numerically and analytically determine the domain of their existence, they have a much larger share of atoms confined in the repulsive condensate. The energy barrier for collapse is due to the fact that the energy of the system increases if atoms tunnel from the repulsive condensate to the attractive one.