A discrete Hubbard-Stratonovich decomposition for general, fermionic two-body interactions

摘要

A scheme is presented to decompose the exponential of a two-body operator ina discrete sum over exponentials of one-body operators. This discretedecomposition can be used instead of the Hubbard-Stratonovich transformation inauxiliary-field quantum Monte-Carlo methods. As an illustration, thedecomposition is applied to the Hubbard model, where it is equivalent to thediscrete Hubbard-Stratonovich transformation introduced by Hirsch, and to thenuclear pairing Hamiltonian.