Quantum speed limit for physical processes

TL;DR

This paper extends the concept of quantum speed limits from unitary to nonunitary processes, providing a lower bound based on quantum Fisher information to evaluate the minimal evolution time in noisy quantum channels.

Contribution

It introduces a new lower bound for the minimal evolution time applicable to nonunitary quantum processes, linked to quantum Fisher information.

Findings

Lower bounds for evolution time in noisy channels derived

Bound connected to quantum Fisher information for time estimation

Applicable to typical nonunitary quantum processes

Abstract

The evaluation of the minimal evolution time between two distinguishable states of a system is important for assessing the maximal speed of quantum computers and communication channels. Lower bounds for this minimal time have been proposed for unitary dynamics. Here we show that it is possible to extend this concept to nonunitary processes, using an attainable lower bound that is connected to the quantum Fisher information for time estimation. This result is used to delimit the minimal evolution time for typical noisy channels.