Energy diffusion and the butterfly effect in inhomogeneous Sachdev-Ye-Kitaev chains
arXiv:1702.08462 · doi:10.21468/SciPostPhys.2.3.018
Abstract
We compute the energy diffusion constant $D$, Lyapunov time $Ï_{\text{L}}$ and butterfly velocity $v_{\text{B}}$ in an inhomogeneous chain of coupled Majorana Sachdev-Ye-Kitaev (SYK) models in the large $N$ and strong coupling limit. We find $D\le v_{\text{B}}^2 Ï_{\text{L}}$ from a combination of analytical and numerical approaches. Our example necessitates the sharpening of postulated transport bounds based on quantum chaos.
10+4 pages, 3 figures; v2: added appendix