Thermal fluctuations and the superfluid to Mott insulator transition

The Cluster Mean Field theory calculation is extended for finite temperatures to study the combined effect of quantum and thermal fluctuations on various phases arising in the spin-1 Bose Hubbard model. This investigation finds that the polar nature of the superfluid phase persists, and the density of bosons with spin component σ = 0 increases with the temperature. The phase diagram is obtained and compared with that of the single-site mean-field theory. Compressibility shows a signature of divergence at the transition from the polar superfluid phase to the normal bose liquid phase. Small thermal fluctuations are sufficient to destroy the anti-ferromagnetic, maximally entangled odd density Mott insulator phase, whereas large thermal fluctuations are needed to break the singlet formed in the even density Mott insulator phase. However, in both the cases, the insulators melt to normal bose liquid at the same temperature.The Cluster Mean Field theory calculation is extended for finite temperatures to study the combined effect of quantum and thermal fluctuations on various phases arising in the spin-1 Bose Hubbard model. This investigation finds that the polar nature of the superfluid phase persists, and the density of bosons with spin component σ = 0 increases with the temperature. The phase diagram is obtained and compared with that of the single-site mean-field theory. Compressibility shows a signature of divergence at the transition from the polar superfluid phase to the normal bose liquid phase. Small thermal fluctuations are sufficient to destroy the anti-ferromagnetic, maximally entangled odd density Mott insulator phase, whereas large thermal fluctuations are needed to break the singlet formed in the even density Mott insulator phase. However, in both the cases, the insulators melt to normal bose liquid at the same temperature.

AIP conference proceedingsJan 1, 20210 citations

Momentum distribution of noncondensate particles near the superfluid-to-Mott-insulator transition of bosonic atoms in a uniform optical lattice

Daw-Wei Wang

We investigate the finite temperature momentum distribution of bosonic noncondensate particles inside a uniform three-dimensional optical lattice near the superfluid-to-Mott-insulator transition point, treating quantum fluctuations and thermal fluctuations on equal footing. We explicitly address the different momentum $(\mathbf{q})$ dependences of quasiparticle distribution resulted from thermal and quantum origins: the former scales as ${|\mathbf{q}|}^{\ensuremath{-}2}$ and hence is dominant in the small momentum region, while the later scales as ${|\mathbf{q}|}^{\ensuremath{-}1}$ and hence is dominant in the large momentum limit. Semianalytical results are derived and therefore can be applied to a further study of strongly interacting bosonic systems. Our results also agree with the scaling theory of a quantum $XY$ model near the transition point.We investigate the finite temperature momentum distribution of bosonic noncondensate particles inside a uniform three-dimensional optical lattice near the superfluid-to-Mott-insulator transition point, treating quantum fluctuations and thermal fluctuations on equal footing. We explicitly address the different momentum $(\mathbf{q})$ dependences of quasiparticle distribution resulted from thermal and quantum origins: the former scales as ${|\mathbf{q}|}^{\ensuremath{-}2}$ and hence is dominant in the small momentum region, while the later scales as ${|\mathbf{q}|}^{\ensuremath{-}1}$ and hence is dominant in the large momentum limit. Semianalytical results are derived and therefore can be applied to a further study of strongly interacting bosonic systems. Our results also agree with the scaling theory of a quantum $XY$ model near the transition point.

arXiv:0905.2837Physical Review ADec 9, 20095 citations

Universal thermodynamics of the superfluid to Mott insulator transition

N. Dupuis, Adam Rançon

Bulletin of the American Physical SocietyMar 7, 20140 citations

From Superfluid to Mott Insulator

ScienceJul 29, 20100 citations

(\mathbf{q})

dependences of quasiparticle distribution resulted from thermal and quantum origins: the former scales as ${|\mathbf{q}|}^{\ensuremath{-}2}$ and hence is dominant in the small momentum region, while the later scales as ${|\mathbf{q}|}^{\ensuremath{-}1}$ and hence is dominant in the large momentum limit. Semianalytical results are derived and therefore can be applied to a further study of strongly interacting bosonic systems. Our results also agree with the scaling theory of a quantum

XY

model near the transition point.