Quantum many-body scars
- Date: Wednesday 13 March 2019, 15:30 – 16:30
- Location: Chemistry West Block SR (1.80)
- Type: Seminars, Chemistry, Seminars, Physics and Astronomy
- Cost: Free
Dr Zlatko Papic, School of Physics and Astronomy, Leeds. Part of the Physical Seminar Series
Abstract: Recent experiments on large chains of Rydberg atoms [H. Bernien et al., Nature 551, 579 (2017)] have demonstrated the possibility of realising 1D quantum simulators with locally constrained Hilbert spaces. These experiments have revealed surprising signatures of non-ergodic dynamics in an apparently thermalising quantum system, for example manifested by persistent oscillations following a quench from the initial Neel state of atoms. In this talk I will argue that this phenomenon is a manifestation of a "quantum many-body scar", i.e., a concentration of extensively many eigenstates of the system around special many-body states . The special states are analogues of unstable classical periodic orbits in the single-particle quantum billiards . I will present a model based on a single particle hopping on the Hilbert space graph, which quantitatively captures the scarred wave functions in large systems that can be numerically simulated. These results suggest that scarred many-body bands give rise to a new universality class of quantum dynamics, which is distinct from thermalisation or localisation, that could be used for creating and manipulating novel states with long-lived coherence in systems that are now available in experiments.  C. J. Turner, A. A. Michailidis, D. A. Abanin, M. Serbyn, Z. Papić, Nat. Phys, 14, 745 (2018).  E. J. Heller, Phys. Rev. Lett. 53, 1515 (1984).