Eur. Phys. J. D 49, 223-230 (2008)
https://doi.org/10.1140/epjd/e2008-00152-9

One-dimensional phase transitions in a two-dimensional optical lattice

¹ Department of Physics, Umeå University, 90187 Umeå, Sweden
² Quantum Research Group, School of Physics, University of KwaZulu-Natal, Private bag X54001, Durban 4000, South Africa
³ Condensed Matter Theory, Department of Theoretical Physics, AlbaNova University Center, KTH, 106 91 Stockholm, Sweden
⁴ NORDITA, AlbaNova University Center, 106 91 Stockholm, Sweden

Corresponding author: ^a lundh@tp.umu.se

Received: 2 May 2008
Revised: 26 June 2008
Published online: 1 August 2008

Abstract

A phase transition for bosonic atoms in a two-dimensional anisotropic optical lattice is considered. If the tunnelling rates in two directions are different, the system can undergo a transition between a two-dimensional superfluid and a one-dimensional Mott insulating array of strongly coupled tubes. The connection to other lattice models is exploited in order to better understand the phase transition. Critical properties are obtained using quantum Monte Carlo calculations. These critical properties are related to correlation properties of the bosons and a criterion for commensurate filling is established.