Imaginary chemical potential and finite fermion density on the lattice - art. no. 054502

Standard lattice fermion algorithms run into the well-known sign problem wi th a real chemical potential. In this paper we investigate the possibility of using an imaginary chemical potential and argue that it has advantages o ver other methods, particularly for probing the physics at finite temperatu re as well as density. As a feasibility study, we present numerical results for the partition function of the two-dimensional Hubbard model with an im aginary chemical potential. We also note that systems with a net imbalance of isospin may be simulated using a real chemical potential that couples to I-3 without suffering from the sign problem. [S0556-2821(99)05203-0].