Premium
Fluctuations and quantum criticality in the two‐dimensional Bose Hubbard model
Author(s) -
Duchon Eric,
Trivedi Nandini
Publication year - 2013
Publication title -
annalen der physik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.009
H-Index - 68
eISSN - 1521-3889
pISSN - 0003-3804
DOI - 10.1002/andp.201300109
Subject(s) - physics , phase diagram , bose–hubbard model , quantum , quantum fluctuation , quantum phase transition , superfluidity , criticality , ground state , phase transition , hubbard model , quantum phases , statistical physics , compressibility , phase (matter) , quantum mechanics , condensed matter physics , superconductivity , nuclear physics , thermodynamics
At a quantum phase transition, one ground state evolves into a different one by passing through a quantum critical region with enhanced spatial and temporal fluctuations. A method to map the quantum critical region using the single, local quantity R, the ratio of compressibility to local number fluctuations is proposed. R can be calculated from in situ experiments and also enables thermometry and phase diagnosis (for example whether superfluid or Mott insulating). The definition of R can be generalized to inhomogeneous systems and provides a powerful tool for experimentally mapping the finite temperature phase diagram demonstrated here for the two‐dimensional Bose Hubbard model.