Many-body localization and symmetry protected topology

Condensed matter theory - cold atoms.

Abstract: Owing to their natural isolation, quantum optical systems of atoms, ions and molecules offer an attractive platform to study out-of-equilibrium quantum dynamics and localization. Recent progress on many-body localized phases has demonstrated that they can exhibit symmetry breaking and/or topological orders in dimensions normally forbidden by Mermin-Wagner arguments. In this talk, I will describe how to coherently prepare, protect and detect symmetry protected topological order in a non-equilibrium setting. I will explore a 1D transverse-field Ising model with periodically driven two-body terms whose Floquet dynamics mirror those of the celebrated Haldane phase. Even in the presence of generic interactions, I will show that disorder leading to many-body localization prevents arbitrary heating of the system and leads to an exponential enhancement of the edge spin coherence at infinite temperature.  Finally, I will describe a natural realization in a Rydberg ensemble, leveraging the blockade to controllably toggle between ferromagnetic and antiferromagnetic Ising interactions.