Higher derivative corrections to incoherent metallic transport in holography
Abstract
Transport in stronglydisordered, metallic systems is governed by diffusive processes. Based on quantum mechanics, it has been conjectured that these diffusivities obey a lower bound D/v ^{2} ≳ ℏ /k _{ B } T , the saturation of which provides a mechanism for the Tlinear resistivity of bad metals. This bound features a characteristic velocity v, which was later argued to be the butterfly velocity v _{ B }, based on holographic models of transport. This establishes a link between incoherent metallic transport, quantum chaos and Planckian timescales. Here we study higher derivative corrections to an effective holographic action of homogeneous disorder. The higher derivative terms involve only the charge and translation symmetry breaking sector. We show that they have a strong impact on the bound on charge diffusion D _{ c }/ ν _{ B } ^{2} ≳ ℏ/ k _{ B } T, by potentially making the coefficient of its righthand side arbitrarily small. On the other hand, the bound on energy diffusion is not affected.
 Publication:

Journal of High Energy Physics
 Pub Date:
 March 2017
 DOI:
 10.1007/JHEP03(2017)170
 arXiv:
 arXiv:1612.05500
 Bibcode:
 2017JHEP...03..170B
 Keywords:

 Holography and condensed matter physics (AdS/CMT);
 AdSCFT Correspondence;
 High Energy Physics  Theory;
 Condensed Matter  Strongly Correlated Electrons
 EPrint:
 v1: 2 plots, 19 pages + appendices