Perturbative Solution of Fermionic Sign Problem in Lattice Quantum Monte Carlo: A Cuprate Case
ORAL
Abstract
We developed a strong coupling perturbation scheme for general Hubbard model around half-field particle-hole symmetric reference system. The approach based on a lattice determinatal Quantum Monte Carlo method in continuous and discrete time versions for a large periodic clusters in a fermionic bath. The first order perturbation in the shift of chemical potential and long-range hopping gives a reasonable accuracy for parameters corresponding to the optimally doped cuprate systems. We calculate spectral function of hole doped t-t'-U model for interaction strength equal to the band width and discuss a mechanism of the pseudogap formation. Results for standard cuprates model with U=8t=W and t'/t=-0.3 for temperatures of the order of T=0.1t show formation of the pseudo-gap and Fermi-arcs. We discuss the magnetic and superconducting instability using symmetry broken external fields.
*M.I.K. and A.I.L. was supported by by European Research Council via Synergy Grant 854843 - FASTCORR.This work used Expanse at SDSC through allocation DMR130036 from the Extreme Science and Engineering Discovery Environment (XSEDE), which was supported by National Science Foundation grant number 1548562.
–
Presenters
-
Alexander I Lichtenstein
- University of Hamburg
- Institute of Theoretical Physics, University of Hamburg, 20355 Hamburg, Germany