Towards a unified approach to information-disturbance tradeoffs in quantum measurements

TL;DR

This paper unifies various approaches to understanding the fundamental tradeoff between information gain and disturbance in quantum measurements by analyzing the overall information dynamics.

Contribution

It introduces a global balance framework that consolidates different methods used to derive information-disturbance tradeoffs in quantum theory.

Findings

Unified framework for information-disturbance tradeoffs

Applicable to multiple definitions of disturbance

Clarifies relationships between different approaches

Abstract

We show that the global balance of information dynamics for general quantum measurements given in [F. Buscemi, M. Hayashi, and M. Horodecki, Phys.Rev.Lett. 100, 210504 (2008)] makes it possible to unify various and generally inequivalent approaches adopted in order to derive information-disturbance tradeoffs in quantum theory. We focus in particular on those tradeoffs, constituting the vast majority of the literature on the subject, where disturbance is defined either in terms of average output fidelity or of entanglement fidelity.