Superdiffusion from Emergent Classical Solitons in Quantum Spin Chains.

  title={Superdiffusion from Emergent Classical Solitons in Quantum Spin Chains.},
  author={Jacopo de Nardis and Sarang Gopalakrishnan and Enej Ilievski and Romain Vasseur},
  journal={Physical review letters},
  volume={125 7},
Finite-temperature spin transport in the quantum Heisenberg spin chain is known to be superdiffusive, and has been conjectured to lie in the Kardar-Parisi-Zhang (KPZ) universality class. Using a kinetic theory of transport, we compute the KPZ coupling strength for the Heisenberg chain as a function of temperature, directly from microscopics; the results agree well with density-matrix renormalization group simulations. We establish a rigorous quantum-classical correspondence between the "giant… 

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