Quantum observable's reality erasure with spacelike-separated operations

TL;DR

This paper demonstrates experimentally that local quantum operations can influence the reality of distant quantum observables without classical communication, challenging local realism principles.

Contribution

It introduces a modified quantum eraser experiment showing that local operations can erase the reality of distant observables without classical communication.

Findings

Alice's operations correlate with erasure of Bob's observable reality

Bob's photon path is not an element of physical reality

Quantum entanglement enables nonlocal influence without classical communication

Abstract

In 1935, Einstein, Podolsky, and Rosen argued that quantum mechanics is incomplete based on the assumption that local actions cannot influence elements of reality at a distant location (local realism). In this work, using a recently defined quantum reality quantifier, we show that Alice's local quantum operations can be correlated with the erasure of the reality of observables in Bob's causally disconnected laboratory. To this end, we implement a modified optical quantum eraser experiment, ensuring that Alice's and Bob's measurements remain causally disconnected. Using an entangled pair of photons and quantum state tomography, we experimentally verify that, even with the total absence of any form of classical communication, the choice of quantum operation applied by Alice on her photon is correlated with the erasure of a spatial element of reality of Bob's photon. Our results reveal that Bob's photon can entangle two extra non-interacting degrees of freedom, thus confirming that Bob's photon path is not an element of physical reality.