Fragmentation, domain formation and atom number fluctuations of a two-species Bose-Einstein condensate in an optical lattice

TL;DR

This paper theoretically investigates how quantum fluctuations influence phase coherence, atom number fluctuations, and domain formation in a two-species Bose-Einstein condensate loaded into a one-dimensional optical lattice, revealing different behaviors in miscible and immiscible regimes.

Contribution

It provides a detailed theoretical analysis of quantum fluctuation effects on coherence and domain formation in two-species BECs in optical lattices, highlighting differences between miscible and immiscible phases.

Findings

Quantum fluctuations reduce phase coherence and atom number fluctuations in the miscible regime.

In the immiscible regime, fluctuations are enhanced, leading to metastable spatially separated domains.

Domain length and fluctuations are significantly affected by quantum effects.

Abstract

We theoretically study the loading of a two-species Bose-Einstein condensate to an optical lattice in a tightly-confined one-dimensional trap. Due to quantum fluctuations the relative inter and intra species phase coherence between the atoms and the on-site atom number fluctuations are reduced in the miscible regime. For the immiscible case the fluctuations are enhanced and the atoms form metastable interleaved spatially separated domains where the domain length and its fluctuations are affected by quantum fluctuations.