On quantum phase transitions in tilted 2D lattices

TL;DR

This paper investigates how tilting a 2D lattice affects quantum phase transitions in cold Bose atoms, revealing that small misalignments prevent the expected ordered state and relate to Bloch oscillations.

Contribution

It demonstrates the critical impact of tilt misalignment on the quantum phase transition outcomes in 2D lattices, linking the phenomenon to Bloch oscillations.

Findings

Small tilt misalignment prevents the formation of the density-wave state.

Adiabatic tilt leads to a disordered state instead of the expected ordered phase.

The problem is related to Bloch oscillations of hard-core bosons in 2D.

Abstract

We discuss the quantum phase transition from the Mott-insulator state to the density-wave state for cold Bose atoms in a 2D square lattice as the lattice is adiabatically tilted along one of its primary axes. It is shown that a small misalignment of the tilt drastically changes the result of the adiabatic passage and, instead of the density-wave state, one obtains a disordered state. Intrinsic relation of the problem to Bloch oscillations of hard-core bosons in a 2D lattice is illuminated.