A variational Monte Carlo study of exciton condensation

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 $\mathbf{k}$-space and in real space are calculated. Using these quantities, we discuss the BCS-BEC crossover within the excitonic insulator phase.

arXiv comment7 pages, 3 figures

References in corpus (9)

• Superconductivity in Cu_xTiSe_2
• Evidence for an excitonic insulator phase in 1T-TiSe${}_2$
• Generalized Lanczos Algorithm for Variational Quantum Monte Carlo
• Monte Carlo study of an unconventional superconducting phase in Ir-oxide J_{eff}=1/2 Mott insulators induced by carrier doping
• Two spin liquid phases in the spatially anisotropic triangular Heisenberg model
• Chiral charge order in 1$T$-TiSe${}_2$: importance of lattice degrees of freedom
• Theoretical study of insulating mechanism in multi-orbital Hubbard models with a large spin-orbit coupling: Slater versus Mott scenario in Sr${}_2$IrO${}_4$
• Exciton-phonon interactions and superconductivity bordering charge order in TiSe2
• Effect of intraband Coulomb repulsion on the excitonic spin-density wave

Cited by in corpus (2)

• Charge-density wave induced by combined electron-electron and electron-phonon interactions in 1$T$-TiSe${}_2$: A variational Monte Carlo study
• Photoinduced enhancement of excitonic order in the two-orbital Hubbard model