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Phase diagram and optical conductivity of the ionic Hubbard model

P. Brune·G. I. Japaridze·A. P. Kampf·M. Sekania
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Abstract

We investigate the ground state phase diagram of the one-dimensional ionic Hubbard model with an alternating potential at half-filling by the bosonization technique as well as by numerical diagonalization of finite systems with the Lanczos and DMRG methods. Our results support the existence of a single "metallic" transition point from a band to a correlated insulator with simultaneous charge and bond-charge order. In addition, we present results for the optical conductivity obtained by the dynamical DMRG method. The insulator-insulator phase transition scenario is discussed in detail including a critical review of existing approaches and results for the ionic Hubbard model.

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P. Brune, G. I. Japaridze, A. P. Kampf, M. Sekania. 2002-07-11. Phase diagram and optical conductivity of the ionic Hubbard model. https://arxiv.org/abs/cond-mat/0106007

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