Criticality-amplified quantum probing of a spontaneous collapse model

TL;DR

This paper proposes a quantum probing method to set upper bounds on parameters of spontaneous collapse models, utilizing quantum criticality in an extended Ising chain to enhance detection sensitivity of the collapse mechanism.

Contribution

It introduces a novel quantum-probing approach combined with quantum criticality to study spontaneous collapse models and derive bounds on their parameters.

Findings

Quantum criticality enhances probing sensitivity.

Out-of-equilibrium states provide early information about collapse.

The method sets bounds on collapse model parameters.

Abstract

Spontaneous collapse models, which are phenomenological mechanisms introduced and designed to account for dynamical wavepacket reduction, are attracting a growing interest from the community interested in the characterisation of the quantum-to-classical transition. Here, we introduce a quantum-probing approach to the quest of deriving metrological upper bounds on the free parameters of such empirical models. To illustrate our approach, we consider an extended quantum Ising chain whose elements are -- either individually or collectively -- affected by a mechanism responsible for spontaneous collapse. We explore configurations involving out-of-equilibrium states of the chain, which allows us to infer information about the collapse mechanism before it is completely scrambled from the state of the system. Moreover, we investigate potential amplification effects on the probing performance based on the exploitation of quantum criticality.