Quantum scrambling with classical shadows

Understand

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.