Signatures of Quantum Chaos in an Out-of-Time-Order Tensor

Motivated by the famous ink-drop experiment, where ink droplets are used to determine the chaoticity of a fluid, we propose an experimentally implementable method for measuring the scrambling capacity of quantum processes. Here, a system of interest interacts with a small quantum probe whose dynamical properties identify the chaoticity of the system. Specifically, we propose a fully quantum version of the out of-time-order correlator-which we term the out-of-time-order tensor-whose correlations offer clear information theoretic meanings about the chaoticity of a process. We illustrate the utility of the out-of-time order tensor as a signature of chaos using random unitary processes as well as in the quantum kicked rotor, where the chaoticity is tunable.

Automated summary

Motivated by the famous ink-drop experiment, the study proposes an experimentally implementable method for measuring the scrambling capacity of quantum processes. The researchers introduce a fully quantum version of the out of-time-order correlator, called the out-of-time-order tensor, which provides clear information about the chaoticity of a process.