Southwest Quantum Information and Technology

Quantum simulation of complex dynamics in a quantum kicked top

Presenting Author: Nathan Lysne, Arizona
Contributing Author(s): Kevin Kuper, Hannah Knaack and Poul Jessen

Recent advances in quantum control have enabled analog quantum simulation (AQS) as a means to study phase changes, order, and other complex many body phenomena. However, as experimental AQS grows in sophistication, new questions arise about our ability to verify the validity of a given simulation. In the absence of error correction, investigating the effects of imperfections on dynamics that is potentially chaotic and hypersensitive to errors is thus essential to understanding how much and in which ways we can trust AQS. The quantum kicked top (QKT) is an ideal model for such studies. We discuss results from recent experiments that use the d = 16 dimensional hyperfine manifold in the 6S1/2 electronic ground state of an individual Cs atom for AQS of a QKT with spin J = 15/2. As a baseline, we see close agreement between simulated and predicted dynamics in a mixed phase space over many tens of kicks. Prior work has shown the QKT dynamics reflects the separation between stable islands and sea of chaos in the classical QK, even in situations where the “fidelity” of the evolving QKT quantum state is poor. This suggests the former represents a “global” property that can be reliably simulated in the presence of errors, even when the microscopic behavior (the quantum state) cannot. We present data from experiments and numerical simulations in the presence of deliberately applied errors, showing that the frequency content of the perturbation plays a central role in the validity and robustness of AQS.​

(Session 4 : Thursday from 3:30pm - 4:00pm)