TY - JOUR
T1 - Variational Study on Loop Currents in Bose Hubbard model with Staggered Flux
AU - Toga, Y.
AU - Yokoyama, H.
N1 - Funding Information:
A part of the numerical computations was carried out at the Cyber-science Center, Tohoku University. This work is partly supported by JSPS KAKENHI Grant Number 25287104.
Publisher Copyright:
© 2015 The Authors.
PY - 2015
Y1 - 2015
N2 - In view of strongly interacting bosons in an optical lattice with a large gauge field, we study phase transitions in a two-dimensional Bose-Hubbard model with a staggered flux, on the basis of variational Monte Carlo calculations. Inthe trial states,besides typical onsite and intersite correlation factors, we introduce a configuration-dependent phase factor,which was recently found essential for treating current-carrying states. It is found that this phase factor is qualitativelyvitalfordescribing a Mott insulating (MI) state in the present model. Thereby, the Peierls phasesattached in relevant hopping processes are cancelled out. As a result, local currents completely suppressed in MI states, namely, a chiral Mott state does not appear for the square lattice, in contrast tothecorresponding two-leg ladder model. In addition, we discuss other features of the first-order superfluid-MI transition in this model.
AB - In view of strongly interacting bosons in an optical lattice with a large gauge field, we study phase transitions in a two-dimensional Bose-Hubbard model with a staggered flux, on the basis of variational Monte Carlo calculations. Inthe trial states,besides typical onsite and intersite correlation factors, we introduce a configuration-dependent phase factor,which was recently found essential for treating current-carrying states. It is found that this phase factor is qualitativelyvitalfordescribing a Mott insulating (MI) state in the present model. Thereby, the Peierls phasesattached in relevant hopping processes are cancelled out. As a result, local currents completely suppressed in MI states, namely, a chiral Mott state does not appear for the square lattice, in contrast tothecorresponding two-leg ladder model. In addition, we discuss other features of the first-order superfluid-MI transition in this model.
KW - Bose-Hubbard model
KW - Mott transition
KW - artificial magnetic filed
KW - cold atom
KW - loop current
KW - optical lattice
KW - staggered flux
KW - variational Monte Carlo method
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U2 - 10.1016/j.phpro.2015.05.102
DO - 10.1016/j.phpro.2015.05.102
M3 - Conference article
AN - SCOPUS:84948396906
SN - 1875-3892
VL - 65
SP - 29
EP - 32
JO - Physics Procedia
JF - Physics Procedia
T2 - 27th International Symposium on Superconductivity, ISS 2014
Y2 - 25 November 2014 through 27 November 2014
ER -