Saved in:
Bibliographic Details
Main Authors: Zhou, Tianci, Brunet, Éric, Qi, Xiaolin
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.06353
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915280055173120
author Zhou, Tianci
Brunet, Éric
Qi, Xiaolin
author_facet Zhou, Tianci
Brunet, Éric
Qi, Xiaolin
contents Operator spreading provides a new characterization of quantum chaos beyond the semi-classical limit. There are two complementary views of how the characteristic size of an operator, also known as the butterfly light cone, grows under chaotic quantum time evolution: A discrete stochastic population dynamics or a stochastic reaction-diffusion equation in the continuum. When the interaction decays as a power function of distance, the discrete population dynamics model features superlinear butterfly light cones with stretched exponential or power-law scaling. Its continuum counterpart, a noisy long-range Fisher-Kolmogorov-Petrovsky-Piscunov (FKPP) equation, remains less understood. We use a mathematical duality to demonstrate their equivalence through an intermediate model, which replaces the hard local population limit by an equilibrium population. Through an algorithm with no finite size effect, we demonstrate numerically remarkable agreements in their light cone scalings.
format Preprint
id arxiv_https___arxiv_org_abs_2505_06353
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Operator Spreading, Duality, and the Noisy Long-Range FKPP Equation
Zhou, Tianci
Brunet, Éric
Qi, Xiaolin
Statistical Mechanics
Disordered Systems and Neural Networks
Operator spreading provides a new characterization of quantum chaos beyond the semi-classical limit. There are two complementary views of how the characteristic size of an operator, also known as the butterfly light cone, grows under chaotic quantum time evolution: A discrete stochastic population dynamics or a stochastic reaction-diffusion equation in the continuum. When the interaction decays as a power function of distance, the discrete population dynamics model features superlinear butterfly light cones with stretched exponential or power-law scaling. Its continuum counterpart, a noisy long-range Fisher-Kolmogorov-Petrovsky-Piscunov (FKPP) equation, remains less understood. We use a mathematical duality to demonstrate their equivalence through an intermediate model, which replaces the hard local population limit by an equilibrium population. Through an algorithm with no finite size effect, we demonstrate numerically remarkable agreements in their light cone scalings.
title Operator Spreading, Duality, and the Noisy Long-Range FKPP Equation
topic Statistical Mechanics
Disordered Systems and Neural Networks
url https://arxiv.org/abs/2505.06353