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Quantum Scrambling and State Dependence of the Butterfly Velocity

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 نشر من قبل Xizhi Han
 تاريخ النشر 2018
  مجال البحث فيزياء
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Operator growth in spatially local quantum many-body systems defines a scrambling velocity. We prove that this scrambling velocity bounds the state dependence of the out-of-time-ordered correlator in local lattice models. We verify this bound in simulations of the thermal mixed-field Ising spin chain. For scrambling operators, the butterfly velocity shows a crossover from a microscopic high temperature value to a distinct value at temperatures below the energy gap.



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