New Anomalous Lieb-Robinson Bounds in Quasiperiodic XY Chains

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.


Published in:
Physical Review Letters, 113, 12, 127202
Year:
Sep 18 2014
ISSN:
0031-9007
1079-7114
Laboratories:




 Record created 2020-10-01, last modified 2020-10-24


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