Benchmarking Information Scrambling

TL;DR

This paper introduces a robust method to accurately benchmark quantum information scrambling, distinguishing genuine scrambling effects from experimental noise and errors, thereby improving the reliability of quantum system diagnostics.

Contribution

The work presents a novel approach to isolate true information scrambling signals from noise in experiments, enhancing the accuracy of quantum benchmarking techniques.

Findings

Effective separation of genuine scrambling from noise

Improved benchmarking accuracy in noisy quantum systems

Robust method applicable to various experimental setups

Abstract

Information scrambling refers to the rapid spreading of initially localized information over an entire system, via the generation of global entanglement. This effect is usually detected by measuring a temporal decay of the out-of-time order correlators. However, in experiments, decays of these correlators suffer from fake positive signals from various sources, e.g., decoherence due to inevitable couplings to the environment, or errors that cause mismatches between the purported forward and backward evolutions. In this work, we provide a simple and robust approach to single out the effect of genuine scrambling. This allows us to benchmark the scrambling process by quantifying the degree of the scrambling from the noisy backgrounds.