Qubit readout and quantum sensing with pulses of quantum radiation

TL;DR

This paper explores how pulses of quantum radiation can be used for qubit readout and quantum sensing, analyzing various measurement strategies and quantum states to optimize sensitivity and information extraction.

Contribution

It introduces a comprehensive framework for modeling quantum probe interactions, enabling direct comparison of different measurement strategies and input states for quantum sensing.

Findings

Quantum trajectories effectively model stochastic measurement records.

Different measurement strategies have distinct metrological advantages.

The framework allows optimization of probe states for enhanced sensitivity.

Abstract

Different hypotheses about a quantum system such as the logical state of a qubit or the value of physical interaction parameters can be investigated by the interaction with a probe field. Such fields may be prepared in particularly sensitive quantum states, and we can use quantum trajectories to model the stochastic measurement record and conditional evolution of the state of the quantum system subject to its interaction with a travelling pulse of radiation. Our analysis applies to different measurement strategies and to arbitrary input quantum states of the probe field pulse and it thus permits direct comparison of their metrological advantages.