Quantum Spinodal Decomposition in Multicomponent Bose-Einstein Condensates

TL;DR

This paper analytically studies the non-equilibrium phase separation process in multicomponent Bose-Einstein condensates, identifying two stages analogous to classical spinodal decomposition and highlighting the role of the Josephson effect.

Contribution

It introduces a detailed analytical model for quantum spinodal decomposition in multicomponent BECs, including the dynamics and time scales of both stages.

Findings

Identification of two distinct stages of phase segregation.

Quantitative estimates of time and length scales in stage I.

Proposal that stage II is dominated by the Josephson effect.

Abstract

We investigate analytically the non-equilibrium spatial phase segregation process of a mixture of alkali Bose-Einstein condensates. Two stages (I and II) are found in analogy to the classical spinodal decomposition. The coupled non-linear Schr\"odinger equations enable us to give a quantitative picture of the present dynamical process in a square well trap. Both time and length scales in the stage I are obtained. We further propose that the stage II is dominated by the Josephson effect between different domains of same condensate different from scenarios in the classical spinodal decomposition. Its time scale is estimated.