@article{23095,
  abstract     = {The PXP chain was recently shown to exhibit superdiffusive energy transport with Kardar-Parisi-Zhang-like
scaling, z ≈ 3/2, joining a growing number of spin chains with this exponent. An understanding of how this
anomalous hydrodynamics emerges from microscopics is, however, still lacking. In this work, we show that
finite-temperature energy transport in this model provides a window into the emergence of superdiffusion. At
finite temperature, the energy autocorrelation function exhibits a crossover from short-time coherent dynamics to
long-time hydrodynamics. The short-time behavior is dominated by a single magnon band and can be understood
analytically. In momentum space, this regime is characterized by spectral weight near q = π. The damping time
τ , which separates the short-time magnon-dominated behavior from the late-time hydrodynamics, grows rapidly
upon cooling, consistent with an activated form τ (β) ∼ βeβ with a gap scale set by the magnon band. At longer
times, the spectral weight transfers to q = 0 and the running decay exponent drifts toward the superdiffusive
value z = 3/2. Finite-temperature energy transport therefore provides a bridge between microscopic magnon
physics and late-time superdiffusion in the PXP model.},
  author       = {Shengtao, Jiang and Desaules, Jean-Yves Marc and Ljubotina, Marko and Scaffidi, Thomas},
  issn         = {2469-9969},
  journal      = {Physical Review B},
  number       = {8},
  publisher    = {American Physical Society},
  title        = {{Finite-temperature crossover from coherent magnons to energy superdiffusion in the PXP model}},
  doi          = {10.1103/mx9k-1mc6},
  volume       = {114},
  year         = {2026},
}