Measurement-Induced Nonlocality

TLDR

Measurement-induced nonlocality is defined as the maximum global effect of locally invariant measurements, a concept dual to the geometric measure of quantum discord. The study aims to quantify measurement‑induced nonlocality geometrically, deriving analytical formulas for arbitrary‑dimensional pure states and 2×n mixed states. The authors derive these analytical formulas for measurement‑induced nonlocality in arbitrary‑dimensional pure states and 2×n mixed states. They establish a tight upper bound for measurement‑induced nonlocality in general cases and discuss its physical significance in terms of correlations, entanglement, quantumness, and cryptographic communication. Citation: Phys.

Abstract

We interpret the maximum global effect caused by locally invariant measurements as measurement-induced nonlocality, which is in some sense dual to the geometric measure of quantum discord [Dakic, Vedral, and Brukner, Phys. Rev. Lett. 105, 190502 (2010)]. We quantify measurement-induced nonlocality from a geometric perspective in terms of measurements, and obtain analytical formulas for any dimensional pure states and 2 × n dimensional mixed states. We further derive a tight upper bound to measurement-induced nonlocality in general case. The physical significance of measurement-induced nonlocality is discussed in the context of correlations, entanglement, quantumness, and cryptographic communication.