Quantum sensors and measurements

Qi Yu, Daoyi Dong, Yuanlong Wang +1 more

Quantum sensing, utilizing quantum techniques to extract key information of a quantum (or classical) system, is a fundamental area in quantum science and technology. For quantum sensors, a basic capability is to uniquely infer unknown parameters in a system based on measurement data from the sensors. In this paper, we investigate the capability of a class of quantum sensors for a spin-12 chain system with unknown parameters. The sensors are composed of qubits which are coupled to the object system and can be initialized and measured. We consider the capability of the single- and two-qubit sensors and show that the capability of single-qubit quantum sensors can be enhanced by adding an extra qubit into the sensor under a certain initialization and measurement setting.

Jincheng Zhang

This paper investigates the application of quantum state entropy measurement to enhance the performance of quantum sensors. Traditional sensing techniques often struggle with the detection of extremely weak signals due to limitations in signal-to-noise ratios. Quantum sensors, leveraging the principles of quantum mechanics, offer the potential for significantly improved sensitivity. However, accurately characterizing the state of the sensor and extracting information from it remains a challenge. Quantum state entropy measurement provides a powerful tool to address this issue by quantifying the uncertainty associated with the sensor's quantum state. This work details the theoretical framework, explores the mathematical underpinnings, and proposes a methodology for utilizing quantum state entropy measurement to improve the precision and sensitivity of quantum sensors. Specifically, we examine the relationship between entropy, sensor state, and the detected signal, outlining a strategy for extracting subtle changes related to the target signal. The core claim of this research is the successful implementation of quantum state entropy measurement for the precise detection of weak signals. ---

Bongs, Kai

Jincheng Zhang

This paper explores the development and potential of quantum sensors utilizing multi-variable measurement. The core concept revolves around leveraging the quantum coherence inherent in quantum sensors to simultaneously measure multiple physical quantities. This is achieved through the design of entangled sensor networks, where the state of one sensor provides information about the states of all interconnected sensors. This approach represents a significant advancement in the field of quantum sensing, offering the possibility of enhanced sensitivity and reduced measurement complexity for applications requiring the simultaneous determination of multiple parameters. The theoretical framework presented here outlines the fundamental principles and explores potential architectures, highlighting the advantages and challenges associated with this technology. We focus on the mathematical underpinnings of entangled sensor systems and the extraction of information from correlated quantum states. ---