Quantum phases of bosons in double-well optical lattices

TL;DR

This paper investigates the quantum phase transitions of bosons in double-well optical lattices, revealing a reentrant transition between superfluid and Mott insulator phases influenced by interchain hopping and tilt.

Contribution

It provides the first detailed phase diagram for bosons in double-well optical lattices, highlighting the non-monotonic behavior of the Mott phase with tilt.

Findings

Reentrant superfluid-Mott transition observed

Phase diagram mapped out with tilt and hopping parameters

Non-monotonic Mott phase behavior as a function of tilt

Abstract

We study the superfluid to Mott insulator transition of bosons in a two-legged ladder optical lattice, of a type accessible in current experiments on double-well optical lattices. The zero-temperature phase diagram is mapped out, with a focus on its dependence upon interchain hopping and the tilt between double wells. We find that the unit-filling Mott phase exhibits a non-monotonic behavior as a function of the tilt parameter, producing a reentrant phase transition between Mott insulator and superfluid phases.