Collective charge excitations and the metal-insulator transition in the square lattice Hubbard-Coulomb model

Understand

In this article, we discuss the non-trivial collective charge excitations (plasmons) of the extended square-lattice Hubbard model.

• Using a fully non-perturbative approach, we employ the hybrid Monte Carlo algorithm to simulate the system at half-filling.
• A modified Backus-Gilbert method is introduced to obtain the spectral functions via numerical analytic continuation.
• We directly compute the single-particle density of states which demonstrates the formation of Hubbard bands in the strongly-correlated phase.