Diagrammatic Quantum Monte Carlo solution of the two-dimensional   Cooperon-Fermion model
  We investigate the two-dimensional cooperon-fermion model in the correlated regime with a new continuous-time diagrammatic determinant quantum Monte Carlo (DDQMC) algorithm. We estimate the transition temperature $T_{c}$, examine the effectively reduced band gap and cooperon mass, and find that delocalization of the cooperons enhances the diamagnetism. When applied to diamagnetism of the pseudogap phase in high-$T_{c}$ cuprates, we obtain results in a qualitative agreement with recent torque magnetization measurements. 
Kai-Yu Yang, E. Kozik, Xin Wang, M. Troyer
cond-mat.supr-con