Title: Quantum Many-body Scar, Entanglement and Correlation
Speaker: Dr. Zhiyuan Yao , Tsinghua University
Time: Mar. 11 (Friday), 10:00
Place: Rm M830, IOP-CAS
Abstract: 
 Recently, quantum many-body scars (QMBS), a small portion of eigenstates that violate the eigenstate thermalization hypothesis, have attracted much interest. QMBS are usually identified by low entanglement entropies compared with those of surrounding thermal states. In this talk, we shall present an alternative diagnosis using the spectrum of correlation matrices. In certain cases, this method has the advantage of singling out scar states using an integer, the degeneracy of zeros of the correlation matrix, and thus is free from finite-size effects. Besides being a diagnosis tool, this method can also be used to construct general families of Hamiltonians hosting a given set of scar states. Furthermore, the spectrum of correlation matrix can, in turn, give an upper bound on the entanglement entropy. We demonstrate the effectiveness and usefulness of our method with several paradigmatic scar states.


About the Speaker:
Zhiyuan Yao is a C. N. Yang postdoctoral fellow at Institute for Advanced Study (IAS), Tsinghua University. He obtained his Ph.D. in physics in 2018 from University of Massachusetts, Amherst under the supervision of Nikolay Prokof’ev and Boris Svistunov. His Ph.D. study focuses on quantum Monte Carlo and theoretical studies of quantum phase transitions in disordered boson systems. After joining IAS, Tsinghua University, his research interests have been mainly motivated by novel phenomena in cold-atom experiments, in particular problems related to thermalization and lattice gauge theory.