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- Title:
Nonlocal emergent hydrodynamics in a long-range quantum spin system
- Document type:
- Zeitschriftenaufsatz
- Author(s):
- Schuckert, Alexander; Lovas, Izabella; Knap, Michael
- Abstract:
- Generic short-range interacting quantum systems with a conserved quantity exhibit universal diffusive transport at late times. We employ nonequilibrium quantum field theory and semiclassical phase-space simulations to show how this universality is replaced by a more general transport process in a long-range XY spin chain at infinite temperature with couplings decaying algebraically with distance as r−α. While diffusion is recovered for α>1.5, longer-ranged couplings with 0.5<α≤1.5 give rise to effective classical Lévy flights, a random walk with step sizes drawn from a distribution with algebraic tails. We find that the space-time-dependent spin density profiles are self-similar, with scaling functions given by the stable symmetric distributions. As a consequence, for 0.5<α≤1.5, autocorrelations show hydrodynamic tails decaying in time as t−1/(2α−1) and linear-response theory breaks down. Our findings can be readily verified with current trapped ion experiments.
- Journal title:
- Physical Review B 2020-01
- Year:
- 2020
- Journal volume:
- 101
- Journal issue:
- 2
- Fulltext / DOI:
- doi:10.1103/physrevb.101.020416
- Publisher:
- American Physical Society (APS)
- E-ISSN:
- 2469-99502469-9969
- Date of publication:
- 28.01.2020
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