Continuous-time quantum Monte Carlo

rdf:langString Continuous-time quantum Monte Carlo

rdf:langString In computational solid state physics, Continuous-time quantum Monte Carlo (CT-QMC) is a family of stochastic algorithms for solving the Anderson impurity model at finite temperature. These methods first expand the full partition function as a series of Feynman diagrams, employ Wick's theorem to group diagrams into determinants, and finally use Markov chain Monte Carlo to stochastically sum up the resulting series. The attribute continuous-time was introduced to distinguish the method from the then-predominant method, which relies on a Suzuki–Trotter discretisation of the imaginary time axis. If the sign problem is absent, the method can also be used to solve lattice models such as the Hubbard model at half filling. To distinguish it from other Monte Carlo methods for such systems that also work in continuous time, the method is then usually referred to as Diagrammatic determinantal quantum Monte Carlo (DDQMC or DDMC).