Exploring a quantum critical point in the 3D Hubbard model using the dynamical cluster approximation

This research simulates the single band three dimensional Hubbard Model using the dynamical cluster approximation. Away from half-filling the system appears to undergo a quantum phase transition driven by the chemical potential or doping level. The quasiparticle weight, extracted from the self-energy, is used to identify the emergence of a Fermi liquid phase. At lower fillings the quasiparticle weight maintains a finite value consistent with a Fermi liquid state. Nearer to half-filling the quasiparticle weight tends towards zero suggesting a non-Fermi liquid state. We also search for evidence of a marginal Fermi liquid state, a signature of the quantum criticality. In order to complete this simulation efficiently the continuous time quantum Monte Carlo method is run on a massively parallel simulation.