The exciton Mott transition and electron‐hole (e‐h) pair condensation are studied using a two‐band Hubbard model with both repulsion and attraction. With the use of the dynamical mean‐field theory, we clarify the phase diagram for the phase transitions at zero and finite temperatures. Away from half‐filling we find an exciton insulating phase, which is followed by the formation of incoherent e‐h pairs, and the first‐order transition between a metallic phase and the exciton insulating phase. We also examine the transition temperature to an e‐h pair condensed phase where BEC‐BCS crossover takes place, and discuss characteristic features of the finite‐temperature phase diagram.The exciton Mott transition and electron‐hole (e‐h) pair condensation are studied using a two‐band Hubbard model with both repulsion and attraction. With the use of the dynamical mean‐field theory, we clarify the phase diagram for the phase transitions at zero and finite temperatures. Away from half‐filling we find an exciton insulating phase, which is followed by the formation of incoherent e‐h pairs, and the first‐order transition between a metallic phase and the exciton insulating phase. We also examine the transition temperature to an e‐h pair condensed phase where BEC‐BCS crossover takes place, and discuss characteristic features of the finite‐temperature phase diagram.

AIP conference proceedingsJan 1, 20063 citations

Chasing the Exciton Condensate

Michael S. Fuhrer, A. R. Hamilton

PhysicsJul 18, 201618 citations

Mott transitions of exciton polaritons and indirect excitons in a periodic potential

Tim Byrnes, Patrik Recher, Y. Yamamoto

We derive an effective Bose-Hubbard model that predicts a phase transition from Bose-Einstein condensate to Mott insulator in two different systems subject to applied periodic potentials: microcavity exciton polaritons and indirect excitons. Starting from a microscopic Hamiltonian of electrons and holes, we derive an effective Bose-Hubbard model for both systems and evaluate the on-site Coulomb interaction $U$ and hopping transition amplitudes $t$ . Experimental parameters required for observing a phase transition between a Bose-Einstein condensate and a Mott insulator are discussed. Our results suggest that strong periodic potentials and polaritons with a very large excitonic component are required for observing the phase transition. The form of the indirect exciton interaction is derived including direct and exchange components of the Coulomb interaction. For indirect excitons, the system crosses over from a Bose-Hubbard model into a double layer Fermi-Hubbard model as a function of increasing bilayer separation. The Fermi-Hubbard model parameters are calculated, and the criteria for the location of this crossover are derived. We conjecture that a crossover between a Bose Mott insulator to a Fermi Mott insulator should occur with increasing bilayer separation.We derive an effective Bose-Hubbard model that predicts a phase transition from Bose-Einstein condensate to Mott insulator in two different systems subject to applied periodic potentials: microcavity exciton polaritons and indirect excitons. Starting from a microscopic Hamiltonian of electrons and holes, we derive an effective Bose-Hubbard model for both systems and evaluate the on-site Coulomb interaction $U$ and hopping transition amplitudes $t$. Experimental parameters required for observing a phase transition between a Bose-Einstein condensate and a Mott insulator are discussed. Our results suggest that strong periodic potentials and polaritons with a very large excitonic component are required for observing the phase transition. The form of the indirect exciton interaction is derived including direct and exchange components of the Coulomb interaction. For indirect excitons, the system crosses over from a Bose-Hubbard model into a double layer Fermi-Hubbard model as a function of increasing bilayer separation. The Fermi-Hubbard model parameters are calculated, and the criteria for the location of this crossover are derived. We conjecture that a crossover between a Bose Mott insulator to a Fermi Mott insulator should occur with increasing bilayer separation.

arXiv:1003.0967Physical Review BMay 14, 201066 citations

Condensation kinetics of excitons

H. Haug

Solid State CommunicationsJan 4, 20054 citations

U

and hopping transition amplitudes

t

. Experimental parameters required for observing a phase transition between a Bose-Einstein condensate and a Mott insulator are discussed. Our results suggest that strong periodic potentials and polaritons with a very large excitonic component are required for observing the phase transition. The form of the indirect exciton interaction is derived including direct and exchange components of the Coulomb interaction. For indirect excitons, the system crosses over from a Bose-Hubbard model into a double layer Fermi-Hubbard model as a function of increasing bilayer separation. The Fermi-Hubbard model parameters are calculated, and the criteria for the location of this crossover are derived. We conjecture that a crossover between a Bose Mott insulator to a Fermi Mott insulator should occur with increasing bilayer separation.