Recently quantum simulators have accessed new regimes of quantum dynamics. Some simulators, however, suffer from qubit-to-qubit variations that can affect the readout in nontrivial ways. In this work, we showed that disordered Rydberg simulators can be operated in a new dynamical regime that is controlled by the presence of quantum scar resonances which exhibit crystalline spatio-temporal correlations. We fully characterized this new regime, finding that the simulator can behave as a time crystal.
Ian Mondragon-Shem, Maxim Vavilov, Ivar Martin, Fate of quantum many-body scars in the presence of disorder, arXiv:2010.10535
Many-body scars in quantum simulators
Recently quantum simulators have accessed new regimes of quantum dynamics. Some simulators, however, suffer from qubit-to-qubit variations that can affect the readout in nontrivial ways. In this work, we showed that disordered Rydberg simulators can be operated in a new dynamical regime that is controlled by the presence of quantum scar resonances which exhibit crystalline spatio-temporal correlations. We fully characterized this new regime, finding that the simulator can behave as a time crystal.
Ian Mondragon-Shem, Maxim Vavilov, Ivar Martin, Fate of quantum many-body scars in the presence of disorder, arXiv:2010.10535
Floquet states of matter are states induced by periodic drives that lead to new dynamical phenomena. We showed that drive-induced states of matter, ranging from anomalous Anderson insulators to time crystals, exhibit a robustly quantized non-adiabatic Berry phase (NBP), thus revealing a universal way to distinguish them from static states of matter. This insight further allowed us to discover new dynamical topological phases by imposing appropriate quantization conditions on the NBP that can be generalized to other systems.
Ian Mondragon-Shem, Ivar Martin, A. Alexandradinata, Meng Cheng. Quantized frequency-domain polarization of driven phases of matter, arXiv:1811.10632 (2018)
Disordered topological phases
Topological crystalline phases (TCP) are topological states protected by spatial symmetries, and constitute a vast part of the known set of topological states. For a long time, it was not clear if they were robust, or if they could be at the very least defined, in the presence of even a single impurity. In this work, we obtained the first rigorous description of topological invariants of TCPs in the presence of disorder and explained the mechanism underlying their robustness.
Ian Mondragon-Shem and Taylor L Hughes, Robust topological invariants of topological crystalline phases in the presence of impurities, arXiv:1906.11847 (2019)