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Energy diffusion and the butterfly effect in inhomogeneous Sachdev-Ye-Kitaev chains
by Yingfei Gu, Andrew Lucas, Xiao-Liang Qi
This Submission thread is now published as
Submission summary
| Authors (as registered SciPost users): | Andrew Lucas |
| Submission information | |
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| Preprint Link: | https://arxiv.org/abs/1702.08462v2 (pdf) |
| Date accepted: | 2017-05-11 |
| Date submitted: | 2017-05-10 02:00 |
| Submitted by: | Lucas, Andrew |
| Submitted to: | SciPost Physics |
| Ontological classification | |
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| Academic field: | Physics |
| Specialties: |
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| Approach: | Theoretical |
Abstract
We compute the energy diffusion constant $D$, Lyapunov time $\tau_{\text{L}}$ 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 $D\le v_{\text{B}}^2 \tau_{\text{L}}$ from a combination of analytical and numerical approaches. Our example necessitates the sharpening of postulated transport bounds based on quantum chaos.
Author comments upon resubmission
List of changes
1) We have added Reference 12 in the introduction as an example of a violation of a postulated relation between charge diffusion and v_B.
2) We have modified the main text in Section 2 around Equations 7-11, along with adding a new Appendix, in order to address a referee's concern that our derivation of the effective action should be more self-contained.
Published as SciPost Phys. 2, 018 (2017)