Complementary sequential measurements generate entanglement

TL;DR

This paper introduces a new approach to understanding the complementarity of two observables through the entanglement generated by sequential measurements, providing bounds relevant for quantum information processing.

Contribution

It establishes a lower bound on entanglement created during sequential measurements, linking fundamental quantum uncertainty with entanglement generation capabilities.

Findings

Provides a lower bound on entanglement from sequential measurements

Connects measurement-induced entanglement to entropic uncertainty relations

Highlights implications for quantum information tasks like decoupling and teleportation

Abstract

We present a new paradigm for capturing the complementarity of two observables. It is based on the entanglement created by the interaction between the system observed and the two measurement devices used to measure the observables sequentially. Our main result is a lower bound on this entanglement and resembles well-known entropic uncertainty relations. Besides its fundamental interest, this result directly bounds the effectiveness of sequential bipartite operations---corresponding to the measurement interactions---for entanglement generation. We further discuss the intimate connection of our result with two primitives of information processing, namely, decoupling and coherent teleportation.