From Mott insulator to band insulator: A dynamical mean-field theory study

摘要: The question if a Mott insulator and band are fundamentally different has been the matter of intensive research recently. Here we consider simple model which allows by tuning one parameter to go continuously from insulator. consists two Hubbard systems connected single particle hopping. Hamiltonian is solved dynamical mean-field theory using Quantum Monte Carlo solve resulting quantum impurity problem. quasiparticle spectral function calculated. focus on optical conductivity in particular Drude weight can be experimentally measured. From our calculation conclude that there continuous crossover phase at finite temperature.