[Aspuru-Guzik group list] Dr. Alexey Rubtsov - HQOC/ITAMP Joint Quantum Sciences Seminar

HQOC/ITAMP Joint Quantum Sciences Seminar Wednesday, October 31st * 4:00 PM * Jefferson 250 Guest Presenter: Dr. Alexey Rubtsov, Moscow State University "Continuous-time Quantum Monte Carlo: at the heart of in silico modeling of correlated systems" A description of strongly correlated quantum ensembles remains a major challenge for physicists. In particular, electron correlations in solids are responsible for the magnetism, high-Tc superconductivity, remarkable optic and transport peculiarities, Kondo physics, etc. Contemporary analysis of correlated solids employs an effective-medium paradigm, so that the description of the entire solid is reduced to so-called impurity model, describing a single atom (or small cluster of atoms) placed in a bath. Although there is no general analytical solution for impurity models, they can be treated numerically, using Continuous-time Quantum Monte Carlo (CT-QMC) family of algorithms. These novel methods are based on a stochastic path-integral calculation for quantum statistical averages. The key ideas and state-of-art achievements of the CT-QMC methods will be discussed; examples of specific calculations will be given. We will also touch an application of CT-QMC to other systems, in particular to the ultracold atom ensembles. Finally, current unresolved issues in the field will be pointed out. *Student presentation by: David Benjamin "Microscopic Theory of Resonant Soft x-ray Scattering" * -- Joan Hamilton Faculty Assistant to Profs. Lukin and Greiner HQOC Administrative Coordinator Harvard University Department of Physics 17 Oxford Street Cambridge, Ma 02138 Phone 617-496-2544 HUCTW Local Representative for the Department of Physics