Special Theory Seminar: Detecting emergent continuous internal symmetries at quantum criticality
Mingru Yang, University of Vienna
Special Theory Seminar at MPQ (lecture hall) and Zoom
Monday, January 30th, 2022, 11:20am (MEZ)
New or enlarged symmetries can emerge at the low-energy spectrum of a Hamiltonian that does not possess the symmetries, if the symmetry breaking terms in the Hamiltonian are irrelevant under the renormalization group flow. In this talk, I will talk about our recently proposed tensor network based algorithm to numerically find lattice operator approximation of the emergent conserved charges in the ground state of any quantum spin chains, without the necessity to have prior knowledge about its low-energy effective field theory. The results obtained with our method shed new light on the emergent conserved charges in the spin-1/2 J-Q Heisenberg model and in a one-dimensional version of deconfined quantum critical points (DQCP). It can also be viewed as a way to extract the local integrals of motion of an integrable model and the local parent Hamiltonian of a critical gapless ground state.