Quantum entangled ground states of two spinor Bose-Einstein condensates

TL;DR

This paper investigates the complex quantum ground states of two spinor Bose-Einstein condensates, revealing entanglement and fragmentation phenomena beyond mean-field approximations through numerical analysis.

Contribution

It provides a detailed non-mean-field phase diagram including quantum fluctuations and introduces a numerical method leveraging conservation laws to analyze entangled ground states.

Findings

Mean-field phase boundaries are largely preserved.

Ground states exhibit fragmentation and entanglement.

Quantum fluctuations significantly affect the ground state properties.

Abstract

We revisit in detail the non-mean-field ground-state phase diagram for a binary mixture of spin-1 Bose-Einstein condensates including quantum fluctuations. The non-commuting terms in the spin-dependent Hamiltonian under single spatial mode approximation make it difficult to obtain exact eigenstates. Utilizing the spin z-component conservation and the total spin angular momentum conservation, we numerically derive the information of the building blocks and evaluate von Neumann entropy to quantify the ground states. The mean-field phase boundaries are found to remain largely intact, yet the ground states show fragmented and entangled behaviors within large parameter spaces of interspecies spin-exchange and singlet-pairing interactions.