Cavity-QED simulator of slow and fast scrambling
Cavity-QED simulator of slow and fast scrambling
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DOI：
10.1103/physreva.99.051803
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发表时间：
2018-10
影响因子：
2.9
通讯作者：
J. Marino;A. Rey
中科院分区：
文献类型：
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作者：
J. Marino;A. Rey
我们研究了由大自旋通过空间不均匀和无公度交换耦合共同相互作用的系统中的信息扰乱，如超时间序关联(OTOCs)所诊断的那样。该模型可在色散区的腔QED系统中实现。当耦合没有分解成一对局域相互作用项的乘积，同时自旋点的状态最初共面于Bloch球的赤道时，观察到由OTOC的指数增长来表示的快速扰乱。当这些条件中的一个没有实现时，OTOC以代数方式增长，其指数对初始状态下的自旋方向敏感。初始条件对扰动动力学的影响归因于整体守恒量的存在，这严重地减慢了接近Bloch球极的初始态的演化。
We study information scrambling, as diagnosed by the out-of-time order correlations (OTOCs), in a system of large spins collectively interacting via spatially inhomogeneous and incommensurate exchange couplings. The model is realisable in a cavity QED system in the dispersive regime. Fast scrambling, signalled by an exponential growth of the OTOCs, is observed when the couplings do not factorise into the product of a pair of local interaction terms, and at the same time the state of the spins points initially coplanar to the equator of the Bloch sphere. When one of these conditions is not realised, OTOCs grow algebraically with an exponent sensitive to the orientation of the spins in the initial state. The impact of initial conditions on the scrambling dynamics is attributed to the presence of a global conserved quantity, which critically slows down the evolution for initial states close to the poles of the Bloch sphere.