COMPUTATIONAL RESEARCH in BOSTON and BEYOND (CRIBB)
Date | January 5, 2024 |
---|---|
Speaker | Rahul Sahay (Harvard) |
Topic | Quantum Spin Lakes: Non-Equilibrium Spin Liquids for Near-Term Quantum Devices |
Abstract |
Dynamical parameter sweeps are ubiquitously used for exploring ground state phase diagrams in analog quantum simulators. However, conventional lore dictates that the presence of unavoidable quantum phase transitions---at which a time-evolving quantum system falls out of equilibrium---limits the ability of these sweeps to prepare interesting equilibrium ground states. In this talk, we counter this lore and show that there are situations where the non-equilibrium nature of a dynamical sweep can enable the creation of exotic states of matter, even in the absence of the desired ground states. For instance, we highlight a non-equilibrium mechanism wherein a simple Hamiltonian parameter sweep can project out anyons and prepare quantum spin liquid (QSL) states, despite the ground state of the Hamiltonian failing to be a QSL. We show > that this mechanism sheds light on recent experimental and numerical observations of the dynamical state preparation of the ruby lattice spin liquid in Rydberg atom arrays. Moreover, this theory suggests a tree tensor network-based numerical tool that quantitatively reproduces the experimental data two orders of magnitude faster than conventional brute-force simulation methods. Time permitting, we highlight that even spin liquid states that are unstable in equilibrium---namely, 2 + 1D U(1) spin liquid states---become accessible by such non-equilibrium dynamics. |
Archives
Acknowledgements
We thank the generous support of MIT IS&T, CSAIL, and the Department of Mathematics for their support of this series.