Equivalence principle and quantum mechanics: quantum simulation with entangled photons

TL;DR

This paper proposes a quantum simulation using entangled photons to explore the validity of Einstein's equivalence principle in non-relativistic quantum mechanics, specifically examining superpositions of mass states.

Contribution

It introduces a photonic quantum simulator capable of emulating superpositions of mass states, challenging the traditional superselection rule and testing the equivalence principle in quantum regimes.

Findings

Photonic simulator can emulate superposition of mass states.

Potential violation of the equivalence principle in quantum superpositions.

Experimental setup based on polarization-entangled photons in curved waveguides.

Abstract

Einstein`s equivalence principle states the complete physical equivalence of a gravitational field and corresponding inertial field in an accelerated reference frame. However, to what extent the equivalence principle remains valid in non-relativistic quantum mechanics is a controversial issue. To avoid violation of the equivalence principle, Bargmann`s superselection rule forbids a coherent superposition of states with different masses. Here we suggest a quantum simulation of non-relativistic Schr\"odinger particle dynamics in non-inertial reference frames, which is based on propagation of polarization-entangled photon pairs in curved and birefringent optical waveguides and Hong-Ou-Mandel quantum interference measurement. The photonic simulator can emulate superposition of mass states, which would lead to violation of the EP.