Composite localized modes in discretized spin-orbit-coupled Bose-Einstein condensates

TL;DR

This paper develops a discrete model for spin-orbit-coupled Bose-Einstein condensates in optical lattices, revealing stable localized states and the impact of SOC on phase transitions akin to semiconductor behavior.

Contribution

It introduces a novel discrete model for SOC BECs in optical lattices, exploring localized states and phase transition mechanisms.

Findings

Stable localized composite states are constructed.

SOC influences the immiscibility-miscibility transition.

The model emulates heavy atom condensates and opposite effective masses.

Abstract

We introduce a discrete model for binary spin-orbit-coupled (SOC) Bose-Einstein condensates (BEC) trapped in a deep one-dimensional optical lattice. Two different types of the couplings are considered, with spatial derivatives acting inside each species, or between the species. The discrete system with inter-site couplings dominated by the SOC, while the usual hopping is negligible, \textit{emulates} condensates composed of extremely heavy atoms, as well as those with opposite signs of the effective atomic masses in the two components.\ Stable localized composite states of miscible and immiscible types are constructed. The effect of the SOC on the immiscibility-miscibility transition in the localized complexes, which emulates the phase transition between insulating and conducting states in semiconductors, is studied.