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arXiv · 1505.02208

A variational Monte Carlo study of exciton condensation

Hiroshi Watanabe·Kazuhiro Seki·Seiji Yunoki
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Abstract

Exciton condensation in a two-band Hubbard model on a square lattice is studied with variational Monte Carlo method. We show that the phase transition from an excitonic insulator to a band insulator is induced by increasing the interband Coulomb interaction. To examine the character of the exciton condensation, the exciton pair amplitudes both in $\bm{k}$-space and in real space are calculated. Using these quantities, we discuss the BCS-BEC crossover within the excitonic insulator phase.

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Hiroshi Watanabe, Kazuhiro Seki, Seiji Yunoki. 2015-05-08. A variational Monte Carlo study of exciton condensation. https://doi.org/10.1088/1742-6596/592/1/012097

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