Abstract:
Numerical simulations of strongly correlated electron
systems suffer from the notorious fermion sign problem which
has prevented progress in understanding if systems like the
Hubbard model display high-temperature superconductivity.
Here we show how the fermion sign problem can be solved
completely with meron-cluster methods in a large class of
models of strongly correlated electron systems, some of
which are in the extended Hubbard model family and show
s-wave superconductivity. In these models we also find that
on-site repulsion can even coexist with a weak chemical
potential without introducing sign problems. We argue that
since these models can be simulated efficiently using
cluster algorithms they are ideal for studying many of the
interesting phenomena in strongly correlated electron
systems.