Measuring the scrambling of quantum information

By Brian Swingle, Gregory S. Bentsen, M. Schleier-Smith, Patrick M. Hayden. 2016

442 citations recorded by the source corpus.

We provide a general protocol to measure out-of-time-order correlation functions. These correlation functions are of broad theoretical interest for diagnosing the scrambling of quantum information in interacting quantum systems and have recently received particular attention in the study of chaos and black holes within holographic duality. Measuring them requires an echo-type sequence in which the sign of a many-body Hamiltonian is reversed. We illustrate our protocol by detailing an implementation employing cold atoms and cavity quantum electrodynamics to probe spin models with nonlocal interactions. To verify the feasibility of the scheme with current technology, we analyze the effects of dissipation in a chaotic kicked-top model. Finally, we propose a number of other experimental platforms where similar out-of-time-order correlation functions can be measured.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/30db8843c3f7f7d0d2ca9bace6e0aaa7ed796d15

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Citations in the corpus

Random Quantum Circuits (2022, background): “OTOCs have been addressed in a range of experiments (181, 182, 183, 184, 105).”
Many-body localization: An introduction and selected topics (2017, unknown): “While there have been important pioneer experiments [211,212], the experimental determination of entanglement dynamics in a scalable two different locations in the system (non-local spin-echo spin-echo protocol) could pick up the weak interaction between the lioms, resulting in different signals for”
Operator Spreading in Random Unitary Circuits (2017, background): “[53] Brian Swingle, Gregory Bentsen, Monika SchleierSmith, and Patrick Hayden, “Measuring the scrambling of quantum information,” Phys.”
Onset of many-body chaos in the $O(N)$ model (2017, background): “Several experimental proposals have also appeared recently [28] [29] [30] that enable one to measure OTO correlators and scrambling and three preliminary experiments have already been carried out [31] [32] [33].”
Slow scrambling in disordered quantum systems (2016, background): “The broad relevance of scrambling in quantum many-body dynamics has also been emphasized [28], for example, scrambling diagnoses the growth of quantum chaos [ 25–27] and the spread of entanglement [ 31].”
Quantum matter built from nanoscopic lattices of atoms and photons (2018, background): “…Black, Chan, and Vuletic, 2003; Gopalakrishnan, Lev, and Goldbart, 2009; Baumann et al., 2010), the behavior of strongly interacting photon “gases” (Peyronel et al., 2012; Bienias et al., 2014; Zeuthen et al., 2017), and even the exploration of quantum information scrambling (Swingle et al., 2016).”
Locality, Quantum Fluctuations, and Scrambling (2018, background): “Although scrambling can also be usefully characterized in entropic terms, OTOCs are more directly measurable, with early experiments having already been carried out in a variety of platforms [17–27].”
Measuring out-of-time-order correlations and multiple quantum spectra in a trapped-ion quantum magnet (2016, methodology): “The Ising Hamiltonian evolution is implemented using the spin–motion coupling described in equation (6).”