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arXiv · 2203.16307

Information spreading and scrambling in disorder-free multiple-spin interacting models

Yoshihito Kuno·Takahiro Orito·Ikuo Ichinose
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Abstract

Tripartite mutual information (TMI) is an efficient observable to quantify the ability of scrambler for unitary time-evolution operator with quenched many-body Hamiltonian. In this paper, we give numerical demonstrations of the TMI in disorder-free (translational invariant) spin models with 3-body and 4-body multiple-spin interactions. The dynamical behavior of the TMI of these models does {\it not} exhibit linear light-cone for sufficiently strong interactions. In early-time evolution, the TMI displays distinct negative increase behavior fitted by a logarithmic-like function. This is in contrast to the conventional linear light-cone behavior present in the XXZ model and its near integrable vicinity. The late-time evolution of the TMI in finite-size systems is also numerically investigated. The multiple-spin interactions make the system nearly integrable and weakly suppress the spread of information and scrambling. The observation of the late-time value of the TMI indicates that the scrambling nature of the system changes by interactions and this change can be characterized by a phase-transition-like behavior of the TMI, reflecting the system's integrability and breaking of eigenstate thermalization hypothesis.

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Yoshihito Kuno, Takahiro Orito, Ikuo Ichinose. 2022-07-25. Information spreading and scrambling in disorder-free multiple-spin interacting models. https://doi.org/10.1103/physreva.106.012435

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