Quantum Monte Carlo with short directed loops

We introduce a new type of directed loop algorithm with short-loop generation for the stochastic series expansion quantum Monte Carlo method[1]. Short-loop algorithms have been shown to greatly improve the dynamics at low temperature in studies of classical spin ice models[2]. We will discuss the framework of this algorithm and make comparisons to the conventional directed loop algorithm in a specific quantum spin model. \newline [1]O.Suljuasen and A. W. Sandvik, Phys. Rev. E66, 046701 (2002). \newline [2]R. Melko et al., Phys. Rev. Lett. 87, 067203 (2001).