Sign problem in Monte Carlo simulations of frustrated quantum spin systems
Sign problem in Monte Carlo simulations of frustrated quantum spin systems
We discuss the sign problem arising in Monte Carlo simulations of frustrated quantum spin systems. We show that for a class of ``semifrustrated'' systems [Heisenberg models with ferromagnetic couplings ${J}_{z}(r)<0$ along the z axis and antiferromagnetic couplings ${J}_{\mathrm{xy}}(r)=\ensuremath{-}{J}_{z}(r)$ in the $\mathrm{xy}$ plane, for arbitrary distances $r],$ the sign problem present …