Positions open
We are looking for postdoc, PhD (GRA) and undergraduate students.
More information about the postdoc positionAbout us
I am a professor of theoretical physics at George Mason University.
My research interest is quantum many-body systems. Earlier in my career, I worked on superconductivity and strongly correlated electronic materials. At Mason, my main focus has been on ultracold quantum gases of interacting atoms or molecules. The underlying theme of my research has remained pretty much the same: to understand the mysteries surrounding various ensembles of interacting quantum particles (e.g. spins, fermions, or bosons) or fields.
My research group approach these many-body problems from several angles.
(1) We have been building numerical algorithms incluing functional renormalization group (FRG). The capacity and performance of this approach never ceased to amaze me since I first learned it from collaborating with Ludwig Mathey, Shan-Wen Tsai, and Charles Clark. Our group implemented and improved FRG for interacting Fermi gases and quantum spin models in two dimensions, and applied them to study dipolar Fermi gases, Rydberg-dressed Fermi gases, and quantum spin models with long-range interactions. Click the Research menu above to see some of the highlights.
(2) New languages and formulations are emerging for quantum many-body physics, which go beyond the traditional wavefunctions, density functionals, Feynman diagrams or path integrals. For instance, my group have tested ansatz based on the tensor network as well as neural network representations of the many-body wavefunction for frustrated quantum spin models. The hope is to find the ground state and extract the order (or the lack thereof) from an unbiased variational approach.
(3) The behaviors of quantum systems can be very surprising and perplexing even when the interactions are negligible. A series of work from my group clarified the topological properties of quantum dynamics, e.g. following a quantum quench (a sudden change in the Hamiltonian) and in Floquet (periodically driven) systems. We were able to establish some rigorous relations for links, knots, and various incarnations of monopoles hidden in the quantum dynamics. Recently, we have sought to provide analytical understanding to the non-Hermitian generalizations of Chern insulators and Weyl semimetals.
Sponsors
Our research is generously supported by the Air Force Office of Scientific Research and the National Science Foundation. Previously, it was also sponsored by National Institute of Standards and Technology and Office of Naval Research.