Degree of Complementarity Determines the Nonlocality in Quantum Mechanics

TL;DR

This paper demonstrates that the optimal unsharpness level enabling joint measurement of all dichotomic observables directly influences the degree of nonlocality in quantum mechanics and no-signaling theories.

Contribution

It establishes a quantitative link between measurement unsharpness and nonlocality, extending the understanding of quantum measurement limitations.

Findings

Optimal unsharpness guarantees joint measurement of all dichotomic observables.

Degree of nonlocality is determined by the optimal unsharpness level.

Results apply to quantum mechanics and general no-signaling theories.

Abstract

Complementarity principle is one of the central concepts in quantum mechanics which restricts joint measurement for certain observables. Of course, later development shows that joint measurement could be possible for such observables with the introduction of a certain degree of unsharpness or fuzziness in the measurement. In this paper, we show that the optimal degree of unsharpness, which guarantees the joint measurement of all possible pairs of dichotomic observables, determines the degree of nonlocality in quantum mechanics as well as in more general no-signaling theories.