First- and second-order phase transitions between the uniform and FFLO   excitonic states in the three-chain Hubbard model for Ta2NiSe5
  We examine the free energy and the thermodynamic properties in the three-chain Hubbard model for Ta2NiSe5 to clarify the phase transitions between the uniform and the FFLO excitonic states which are expected to be observed in Ta2NiSe5 under high pressure. 
Kaoru Domon, Takemi Yamada and Yoshiaki \=Ono
cond-mat.str-el