Measuring out-of-time-order correlations and multiple quantum spectra in a trapped-ion quantum magnet

Published

May 22, 2017

Author(s)

Martin Garttner, Justin G. Bohnet, Arghavan Safavi-Naini, Michael L. Wall, John Bollinger, Ana Maria Rey

Abstract

Controllable arrays of ions and ultracold atoms can simulate complex many-body phenomena and may provide insights into unsolved problems in modern science. To this end, experimentally feasible protocols for quantifying the buildup of quantum correlations and coherence are needed, as performing full state tomography does not scale favourably with the number of particles. Here we develop and experimentally demonstrate such a protocol, which uses time reversal of the many-body dynamics to measure out-of-time-order correlation functions (OTOCs) in a long-range Ising spin quantum simulator with more then 100 ions in a Penning trap. By measuring a family of OTOCs as a function of a tunable parameter we obtain fine-grained information about the state of the system encoded in the multiple quantum coherence spectrum, extract the quantum state purity, and demonstrate the buildup of up to 8-body correlations. Future applications of this protocol could enable studies of many-body localization, quantum phase transitions, and tests of the holographic duality between quantum and gravitational systems.

Citation

Nature Physics

Pub Type

Journals

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Keywords

coherence, Ising spin, Penning trap, quantum, ultracold atoms

Citation

Garttner, M. , Bohnet, J. , Safavi-Naini, A. , Wall, M. , Bollinger, J. and Rey, A. (2017), Measuring out-of-time-order correlations and multiple quantum spectra in a trapped-ion quantum magnet, Nature Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=926600 (Accessed July 1, 2024)