Detecting Classically Undetectable Particles through Quantum Decoherence

TL;DR

This paper proposes detecting extremely weakly interacting particles, such as sub-MeV dark matter or gravitons, by observing their decoherent effects on quantum devices, offering a new approach beyond traditional energy transfer methods.

Contribution

It introduces a novel method for detecting classically undetectable particles via quantum decoherence effects on matter interferometers.

Findings

Decoherence can reveal particles with negligible classical interactions.

Quantum devices can detect feeble particles like sub-MeV dark matter or gravitons.

The approach broadens the scope of particle detection beyond energy transfer.

Abstract

Some hypothetical particles are considered essentially undetectable because they are far too light and slow-moving to transfer appreciable energy or momentum to the normal matter that composes a detector. I propose instead directly detecting such feeble particles, like sub-MeV dark matter or even gravitons, through their uniquely distinguishable decoherent effects on quantum devices like matter interferometers. More generally, decoherence can reveal phenomena that have arbitrarily little classical influence on normal matter, giving new motivation for the pursuit of macroscopic superpositions.