Experimental Test of Nonlocality Limits from Relativistic Independence

TL;DR

This paper experimentally tests a relativistic principle that bounds quantum nonlocal correlations, using weak measurements on entangled photons to explore the fundamental limits imposed by quantum uncertainty.

Contribution

It provides an experimental validation of a new bound on quantum correlations derived from the principle of Relativistic Independence, using innovative weak measurement techniques.

Findings

Confirmed the existence of a fundamental limit on quantum correlations.

Demonstrated the role of uncertainty in balancing local and nonlocal quantum correlations.

Used sequential and joint weak measurements to quantify correlations without collapsing the quantum state.

Abstract

Quantum correlations, like entanglement, represent the characteristic trait of quantum mechanics, and pose essential issues and challenges to the interpretation of this pillar of modern physics. Although quantum correlations are largely acknowledged as a major resource to achieve quantum advantage in many tasks of quantum technologies, their full quantitative description and the axiomatic basis underlying them are still under investigation. Previous works suggested that the origin of nonlocal correlations is grounded in principles capturing (from outside the quantum formalism) the essence of quantum uncertainty. In particular, the recently-introduced principle of Relativistic Independence gave rise to a new bound intertwining local and nonlocal correlations. Here we test such a bound by realizing together sequential and joint weak measurements on entangled photon pairs, allowing to simultaneously quantify both local and nonlocal correlations by measuring incompatible observables on the same quantum system without collapsing its state, a task typically forbidden in the traditional (projective) quantum measurement framework. Our results demonstrate the existence of a fundamental limit on the extent of quantum correlations, shedding light on the profound role of uncertainty in both enabling and balancing them.