Quantum Information Scrambling in Systems with Nonlocal Interactions

Darvin Wanisch, Juan Diego Arias Espinoza, Stephan Fritzsche

Published 2022-09-19Version 1

How fast quantum information scrambles such that it becomes inaccessible by local probes turns out to be central to various fields. Motivated by recent works on spin systems with nonlocal interactions, we study information scrambling in different variants of the Ising model. Our work reveals operator dynamics in the presence of nonlocal interactions not precisely captured by out-of-time-order correlators (OTOCs). In particular, the operator size exhibits a slowdown in systems with generic powerlaw interactions despite a highly nonlinear lightcone. A recently proposed microscopic model for fast scrambling does not show this slowdown, which uncovers a distinct analogy between a local operator under unitary evolution and the entanglement entropy following a quantum quench. Our work gives new insights on scrambling properties of systems in reach of current quantum simulation platforms and complements results on possibly observing features of quantum gravity in the laboratory.