Kind of entanglement that speeds up quantum evolution

TL;DR

This paper explores how a specific type of entanglement accelerates quantum evolution by relating it to Fisher information, providing a tighter bound on evolution speed and deepening understanding of entanglement's role in quantum dynamics.

Contribution

It introduces a refined uncertainty relation involving Fisher information, offering a new perspective on the link between entanglement and quantum evolution speed.

Findings

Fisher information provides a tighter bound on quantum evolution speed.

Entangled states can evolve faster due to increased Fisher information.

A new lower bound on passage time is established based on Fisher information.

Abstract

The "speed" of unitary quantum evolution was recently shown to be connected to entanglement in multipartite quantum systems. Here, we discuss a tighter version of the Mandelstam-Tamm uncertainty relation that depends on the Fisher information. The passage time is estimated by a lower bound that depends inversely proportional to the square root of the Fisher information. This leads to a better understanding of the origin of a fast quantum time evolution of entangled states.