Frequency Measurement with Superradiant Pulses of Incoherently Pumped Calcium Atoms: Role of Quantum Measurement Backaction

TL;DR

This paper investigates how quantum measurement backaction influences frequency measurement using superradiant pulses from incoherently pumped calcium atoms, introducing a stochastic mean field theory to model these effects.

Contribution

It presents a theoretical framework analyzing quantum measurement backaction on superradiant calcium atoms, extending modeling techniques to incoherent pumping scenarios.

Findings

Quantum measurement backaction significantly affects superradiant pulse dynamics.

The developed stochastic mean field theory accurately models frequency measurement processes.

Backaction plays a crucial role in the collective spin and emitted field behavior.

Abstract

A recent experiment demonstrated heterodyne detection-based frequency measurements with superradiant pulses from coherently pumped strontium atoms in an optical lattice clock system, while another experiment has analyzed the statistics of superradiant pulses from incoherently pumped calcium atoms in a similar system. In this article, we propose to perform heterodyne detection of the superradiant pulses from the calcium atoms, and analyze theoretically the corresponding atomic ensemble dynamics in terms of the rotation of a collective spin vector and the incoherent quantum jumps among superradiant Dicke states. We examine the effect of quantum measurement backaction on the emitted field and the collective spin vector dynamics, and we demonstrate that it plays an essential role in the modelling of the frequency measurements. We develop a stochastic mean field theory, which is also applicable to model frequency measurements with steady-state superradiance signals, and to explore quantum measurement effects in the dynamics of atomic ensembles.