Measuring out-of-time-order correlations and multiple quantum spectra in a trapped-ion quantum magnet
Measuring out-of-time-order correlations and multiple quantum spectra in a trapped-ion quantum magnet
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DOI：
10.1038/nphys4119
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发表时间：
2017-08-01
期刊：
影响因子：
19.6
通讯作者：
Rey, Ana Maria
中科院分区：
文献类型：
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作者：
Garttner, Martin;Bohnet, Justin G.;Rey, Ana Maria
离子和超冷原子的可控阵列可以模拟复杂的多体现象，并可能为现代科学中未解决的问题提供见解。为此，需要用于量化量子相关性和相干性的建立的实验可行的协议，因为执行全状态断层扫描并不随着粒子的数量而有利地缩放。在这里，我们开发和实验证明这样一个协议，它使用多体动力学的时间反转来测量的时间顺序相关函数（OTOC）在远程伊辛自旋量子模拟器与超过100个离子在潘宁陷阱。通过测量一个家庭的OTOC作为一个可调参数的函数，我们获得细粒度的信息编码在多量子相干谱的系统的状态，提取的量子态纯度，并证明了高达8体相关的建设。该协议的未来应用可以使多体局域化，量子相变的研究，量子和引力系统之间的全息对偶性的测试。
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 than 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.