Understanding the properties of quantum matter remains one of the great challenges in physics and chemistry. Computation has an integral role to play in tackling this challenge. I will give an introduction to the fundamental issues facing accurate and predictive computations of quantum systems, and then describe recent progress in combining field-theory and Monte Carlo simulations for computations in many-electron systems. This computational framework can be used to simulate either a fully materials-specific Hamiltonian or a Hubbard-like model — or indeed any electronic Hamiltonian in between as the former is “down-folded‘’ to the latter.  We illustrate the approach with a few examples in condensed matter physics and quantum chemistry, and discuss opportunities for its applications as well as improvement and optimizations.

Shiwei Zhang received a B.S. in Physics from the University of Science and Technology of China in 1988. He then attended Cornell University via the CUSPEA program and received a Ph.D. in Physics in 1993.  After two years at Los Alamos National Laboratory as a Postdoctoral Research Associate and then briefly at Ohio State University as an NSF Postdoctoral Fellow and University Postdoctoral Fellow, he joined the faculty at William and Mary in 1996, where he is now Professor of Physics. Dr. Zhang is a Fellow of the American Physical Society. He has received a number of awards, including the NSF Faculty CAREER Award, the Cottrell Scholar Award, and the Plumeri Award for Faculty Excellence. He is principal investigator of multiple research collaboration teams of leading US institutions. He has made many fundamental contributions in the computational studies of quantum systems. Methods he pioneered have been applied in condensed matter physics, quantum chemistry, ultra-cold atoms, and nuclear physics.