Continuous time quantum Monte Carlo method for fermions: beyond auxiliary field framework
A. N. Rubtsov+, A. I. Lichtenstein* 1)
+Physics department, Moscow State University, 119992 Moscow, Russia
*Institute of Theoretical Physics, University of Hamburg, 20355 Hamburg, Germany
PACS: 02.70.Ss, 71.10.Fd, 71.27.+a
Abstract
Numerically exact continuous-time Quantum Monte Carlo
algorithm for finite fermionic systems with non-local interactions
is proposed. The scheme is particularly applicable for general
multi-band time-dependent correlations since it does not invoke
Hubbard-Stratonovich transformation. The present determinantal
grand-canonical method is based on a stochastic series expansion
for the partition function in the interaction representation. The
results for the Green function and for the time-dependent
susceptibility of multi-orbital super-symmetric impurity model
with a spin-flip interaction are presented.