A binary mixture of spinor atomic Bose-Einstein condensates

TL;DR

This paper analyzes the phase diagram of a mixture of two spin-1 Bose-Einstein condensates, providing analytical and numerical insights into quantum phase transitions relevant for ongoing experiments.

Contribution

It offers the first detailed phase diagram of mixed spinor condensates, including analytical solutions without singlet pairing and numerical results with pairing interactions.

Findings

Analytical ground state phases without singlet pairing.

Numerical phase diagram with singlet pairing interaction.

Identification of quantum phase transition boundaries.

Abstract

We study the ground state and classify its phase diagram for a mixture of two spin-1 condensates in the absence of external magnetic (B-) field according to atomic parameters for intra- and inter-species spin exchange coupling and singlet pairing interaction. Ignoring the inter-species singlet pairing interaction, the ground state phases are found analytically. Numerical approach of simulated annealing is adopted when the singlet pairing interaction is present. Our results on the phase diagram and the boundaries between phases allow for easy identifications of quantum phase transitions, that can be induced through the tuning of optical traps and atom numbers. They provide the first insight and guidance for several ongoing experiments on mixtures of spinor condensates.