research article
New Anomalous Lieb-Robinson Bounds in Quasiperiodic XY Chains
September 18, 2014
We announce and sketch the rigorous proof of a new kind of anomalous (or sub-ballistic) Lieb-Robinson (LR) bound for an isotropic XY chain in a quasiperiodic transversal magnetic field. Instead of the usual effective light cone |x|≤v|t|, we obtain |x|≤v|t|α for some 0<α<1. We can characterize the allowed values of α exactly as those exceeding the upper transport exponent α+u of a one-body Schrödinger operator. To our knowledge, this is the first rigorous derivation of anomalous quantum many-body transport. We also discuss anomalous LR bounds with power-law tails for a random dimer field.
Type
research article
Author(s)
Date Issued
2014-09-18
Published in
Volume
113
Issue
12
Article Number
127202
Editorial or Peer reviewed
REVIEWED
Written at
OTHER
EPFL units
Available on Infoscience
October 1, 2020
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