A new paper by Nicole Yunger Halpern, Brian Swingle and Justin Dressel combines the out-of-time-ordered correlator (OTOC) and the Kirkwood-Dirac (KD) quasiprobability.Two topics, evolving rapidly in separate fields, were combined recently: the out-of-time-ordered correlator (OTOC) signals quantum-information scrambling in many-body systems. The Kirkwood-Dirac (KD) quasiprobability represents operators in quantum optics. The OTOC was shown to equal a moment of a summed quasiprobability [Yunger Halpern, Phys. Rev. A 95, 012120 (2017)]. That quasiprobability, we argue, is an extension of the KD distribution. We explore the quasiprobability’s structure from experimental, numerical, and theoretical perspectives.
This work not only illuminates the OTOC’s underpinnings, but also generalizes quasiprobability theory and motivates immediate-future weak-measurement challenges.
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