Quantum interference in external gravitational fields beyond General Relativity

Luca Buoninfante,Gaetano Lambiase,Luciano Petruzziello

doi:10.1140/epjc/s10052-021-09740-2

Abstract

In this paper, we study the phenomenon of quantum interference in the presence of external gravitational fields described by alternative theories of gravity. We analyze both non-relativistic and relativistic effects induced by the underlying curved background on a superposed quantum system. In the non-relativistic regime, it is possible to come across a gravitational counterpart of the Bohm–Aharonov effect, which results in a phase shift proportional to the derivative of the modified Newtonian potential. On the other hand, beyond the Newtonian approximation, the relativistic nature of gravity plays a crucial rôle. Indeed, the existence of a gravitational time dilation between the two arms of the interferometer causes a loss of coherence that is in principle observable in quantum interference patterns. We work in the context of generalized quadratic theories of gravity to compare their physical predictions with the analogous outcomes in general relativity. In so doing, we show that the decoherence rate strongly depends on the gravitational model under investigation, which means that this approach turns out to be a promising test bench to probe and discriminate among all the extensions of Einstein’s theory in future experiments.

Highlights

Einstein’s general relativity (GR) has gone through many challenges in the last century, but it has always been confirmed by high-precision experiments which have verified many of its predictions [1]
Since we have reviewed the concept of quantum complementarity and the physical properties of the interferometric setup under consideration, we are ready to study the phenomenon of quantum interference in an external gravitational field
We have studied the phenomenon of quantum interference in an external gravitational field beyond Einstein’s GR

Summary

Introduction

Einstein’s general relativity (GR) has gone through many challenges in the last century, but it has always been confirmed by high-precision experiments which have verified many of its predictions [1]. By focusing on galactic and cosmological scales, self-consistent and complete descriptions for dark matter and dark energy (which are both compatible with experimental data) are still missing. In the short-distance (ultraviolet) regime, GR turns out to be classically incomplete due to the presence of cosmological and black hole singularities, whereas from a quantum point of view it is a nonrenormalizable theory, which lacks predictability at high energies. From an experimental point of view, what we can say is that our knowledge about short-distance gravity is extremely limited; Newton’s law has been tested only up to micrometer scales [3] and the smallest masses for which the gravitational coupling has been measured are of the order of 100 milligrams [4]

Objectives

Discussion

Conclusion