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arXiv · 1405.4511

Finite-temperature phase transitions in the ionic Hubbard model

Aaram J. Kim·M. Y. Choi·Gun Sang Jeon
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Abstract

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.

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Aaram J. Kim, M. Y. Choi, Gun Sang Jeon. 2014-05-18. Finite-temperature phase transitions in the ionic Hubbard model. https://doi.org/10.1103/physrevb.89.165117

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