We demonstrate analytically and verify numerically that the out-of-time order correlator is given by the thermal average of Loschmidt echo signals. This provides a direct link between the out-of-time-order correlator -- a recently suggested measure of information scrambling in quantum chaotic systems -- and the Loschmidt echo, a well-appreciated familiar diagnostic that captures the dynamical aspect of chaotic behavior in the time domain, and is accessible to experimental studies.
@article{arxiv.1903.02651,
title = {Information Scrambling and Loschmidt Echo},
author = {Bin Yan and Lukasz Cincio and Wojciech H. Zurek},
journal= {arXiv preprint arXiv:1903.02651},
year = {2020}
}
Comments
V4: final version for publication; improved presentation; 6+8 pages, 5 figures. V3: a major improvement of an already good paper