Finite-temperature phase transitions in the ionic Hubbard model

Article

关键词: STRONG ELECTRON CORRELATION;    MIXED-STACK COMPOUNDS;    MEAN-FIELD THEORY;    INFINITE DIMENSIONS;    MOTT INSULATOR;    BAND INSULATOR;    CHARGE;    SPIN;    SUPERCONDUCTORS;    TRANSFORMATION;   

DOI  :  10.1103/PhysRevB.89.165117

来源: SCIE

【 摘 要 】

We investigate paramagnetic metal-insulator transitions in the infinite-dimensional ionic Hubbard model at finite temperatures. By means of the dynamical mean-field theory with an impurity solver of the continuous-time quantum Monte Carlo method, we show that an increase in the interaction strength brings about a crossover from a band insulating phase to a metallic one, followed by a first-order transition to a Mott insulating phase. The first-order transition turns into a crossover above a certain critical temperature, which becomes higher as the staggered lattice potential is increased. Further, analysis of the temperature dependence of the energy density discloses that the intermediate metallic phase is a Fermi liquid. It is also found that the metallic phase is stable against strong staggered potentials even at very low temperatures.

【 授权许可】

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