Quantum scrambling with classical shadows

Quantum dynamics is of fundamental interest and has implications in quantum information processing. The four-point out-of-time-ordered correlator (OTOC) is traditionally used to quantify quantum information scrambling under many-body dynamics. Due to the OTOC's unusual time ordering, its measur...

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Bibliographic Details
Main Authors: Roy J. Garcia, You Zhou, Arthur Jaffe
Format: Article
Language:English
Published: American Physical Society 2021-08-01
Series:Physical Review Research
Online Access:http://doi.org/10.1103/PhysRevResearch.3.033155
Description
Summary:Quantum dynamics is of fundamental interest and has implications in quantum information processing. The four-point out-of-time-ordered correlator (OTOC) is traditionally used to quantify quantum information scrambling under many-body dynamics. Due to the OTOC's unusual time ordering, its measurement is challenging. We propose higher-point OTOCs to reveal early-time scrambling behavior, and present protocols to measure any higher-point OTOC using the shadow estimation method. The protocols circumvent the need for time-reversal evolution and ancillary control. They can be implemented in near-term quantum devices with single-qubit readout.
ISSN:2643-1564