Details
Speaker Name/Affiliation
Anton Kapustin / Caltech
When
-
Seminar Type
Location (Room)
Duane Physics Room G126
Event Details & Abstracts
Abstract: The long-wavelength response of a gapped many-body system in D spatial dimensions with a Lie group symmetry G to an external gauge field is believed to be described by a Chern-Simons action in dimension D+1. Since the coefficient of the Chern-Simons action is quantized, it is a topological invariant (i.e. is unchanged under deformations of the Hamiltonian which do not close the gap). I will explain how this invariant can be extracted, in principle, directly from the ground-state wavefunction of a lattice system. This construction also shows that the Chern-Simons invariant can be viewed as a special case of the many-body Berry phase.
======
Please contact Andrew.J.Lucas@Colorado.EDU for more information.
The Physics Frontiers Centers (PFC) program supports university-based centers and institutes where the collective efforts of a larger group of individuals can enable transformational advances in the most promising research areas. The program is designed to foster major breakthroughs at the intellectual frontiers of physics by providing needed resources such as combinations of talents, skills, disciplines, and/or specialized infrastructure, not usually available to individual investigators or small groups, in an environment in which the collective efforts of the larger group can be shown to be seminal to promoting significant progress in the science and the education of students. PFCs also include creative, substantive activities aimed at enhancing education, broadening participation of traditionally underrepresented groups, and outreach to the scientific community and general public.