Cavity-aided quantum parameter estimation in a bosonic double-well Josephson junction

TL;DR

This paper presents a cavity-based measurement system for non-demolition, high-precision estimation of population imbalance in a Bose-Einstein condensate within a double-well optical cavity, enabling quantum-limited parameter inference.

Contribution

It introduces a novel apparatus that allows for minimally invasive, highly accurate quantum parameter estimation of a BEC in a double-well system using cavity interactions.

Findings

Enables weakly disturbing measurements of population imbalance.

Facilitates quantum-limited estimation of system parameters.

Supports Hamiltonian diagnosis via cavity field measurements.

Abstract

We describe an apparatus designed to make non-demolition measurements on a Bose-Einstein condensate (BEC) trapped in a double-well optical cavity. This apparatus contains, as well as the bosonic gas and the trap, an optical cavity. We show how the interaction between the light and the atoms, under appropriate conditions, can allow for a weakly disturbing yet highly precise measurement of the population imbalance between the two wells and its variance. We show that the setting is well suited for the implementation of quantum-limited estimation strategies for the inference of the key parameters defining the evolution of the atomic system and based on measurements performed on the cavity field. This would enable {\it de facto} Hamiltonian diagnosis via a highly controllable quantum probe.