The field of quantum sensing leverages quantum mechanical resources such as superposition, entanglement, and squeezing to surpass classical limits in measurement precision and enable new sensing modalities. This Special Topic Collection in Applied Physics Reviews brings together recent advances spanning theory, materials, device engineering, and applications of quantum sensors. Contributions cover a wide range of platforms, including atomic, solid-state, optomechanics, and photonics, highlighting both fundamental science and emerging technologies. The collection illustrates the transition of quantum sensing from foundational concepts toward scalable technologies and broadens its impact across physics, engineering, and applied sciences.
The field of quantum sensing leverages quantum mechanical resources such as superposition, entanglement, and squeezing to surpass classical limits in measurement precision and enable new sensing modalities. This Special Topic Collection in Applied Physics Reviews brings together recent advances spanning theory, materials, device engineering, and applications of quantum sensors. Contributions cover a wide range of platforms, including atomic, solid-state, optomechanics, and photonics, highlighting both fundamental science and emerging technologies. The collection illustrates the transition of quantum sensing from foundational concepts toward scalable technologies and broadens its impact across physics, engineering, and applied sciences.
Quantum sensing leverages the properties of quantum systems-such as energy quantization, superposition, and entanglement -to achieve sensitive measurements.[1] Quantum sensors can be based on various platforms, such as photons, cold atoms, solid-state spin qubits, and superconducting circuits, for different applications.Over the last decade, quantum sensing has not only opened new avenues for precision measurement in various scientific domains [2,3] but also made remarkable breakthroughs in biomedical, navigation, energy, and other applications.[4-6] To enhance the benefits of quantum sensing, it is crucial to address challenges related to materials [7] and system engineering [8] to improve sensitivity, reliability, and real-time monitoring.Current research efforts span a diverse range of scientific and technological advancements to address these issues and enable new applications.The Special Issue "Quantum Sensing," edited by Tongcang Li, Renbao Liu, and Chong Zu, features 2 review articles and 13 original articles, reporting the latest advancements in the field.This
Quantum technologies are at the cusp of a new technological revolution, with quantum computing and quantum sensing emerging as two of its most transformative domains. This review paper provides an in-depth analysis of these fields, exploring their fundamental principles, hardware implementations, and the challenges that hinder their widespread adoption. Quantum computing, leveraging superposition and entanglement, promises to solve intractable computational problems in areas like drug discovery, materials science, and cryptography. Concurrently, quantum sensing exploits the inherent sensitivity of quantum systems to external perturbations, enabling unprecedented precision in metrology, medical diagnostics, and navigation. We delve into the diverse hardware platforms for each field, including superconducting qubits, trapped ions, NV centers in diamond, and cold atoms. A central theme of this review is the symbiotic relationship between quantum computing and quantum sensing, illustrating how advancements in one area directly accelerate progress in the other. Finally, we discuss the current state of the art, identify key technical and engineering challenges, and provide an outlook on future directions and potential societal impacts.
Quantum sensors and metrology harness quantum phenomena—such as superposition, entanglement, and squeezing—to achieve precision measurements beyond classical limits. This review presents an overview of the fundamental principles underlying quantum sensing, including quantum coherence, entanglement-assisted measurement, and quantum-enhanced interferometry. Various quantum sensor platforms are discussed, including atomic clocks, nitrogen-vacancy (NV) center magnetometers, superconducting quantum interference devices (SQUIDs), optomechanical sensors, and trapped-ion systems. We explore their operational mechanisms, performance metrics, and technological implementations. Comparative analyses highlight sensitivity, spatial resolution, bandwidth, and environmental robustness. Advances in materials, control techniques, and hybrid architectures are examined, and emerging applications in navigation, geophysics, medical imaging, and fundamental physics are reviewed. Finally, future prospects for scalable and robust quantum metrology are discussed.
Background: High-precision sensing is vital for modern technology, yet conventional sensors are fundamentally constrained by classical noise limits. Quantum sensing leverages principles of quantum mechanics, such as superposition and entanglement, to overcome these barriers, offering unprecedented sensitivity. This review comprehensively analyzes the current state of quantum sensor technology, focusing on its underlying physical principles, emerging applications, and the pathway toward industrial maturation.Methods: We synthesize findings from key research areas, detailing the foundational quantum systems like Nitrogen-Vacancy (NV) centers in diamond and advanced optical techniques. The paper reviews the theoretical methods used to achieve sub-shot-noise performance and discusses the system-level engineering challenges necessary for practical deployment, particularly concerning microwave control and optical readout. We also assess the current landscape of standardization efforts for quantum technologies.Results: Significant breakthroughs are highlighted in both biomedical and environmental sensing. Applications range from tracking cellular redox-status using electron-paramagnetic resonance to ultra-sensitive salinity measurements. The analysis confirms that quantum sensing provides superior resolution compared to classical counterparts, unlocking new capabilities in in-vivo and real-time monitoring.Discussion: While offering transformative potential, widespread adoption faces hurdles, including the maintenance of quantum coherence in ambient environments and the high cost and complexity of current instrumentation. Future efforts must focus on miniaturization, integration with classical systems, and standardized fabrication protocols. Quantum sensing represents the next-generation technological paradigm for metrology.
This monograph presents the emerging field of second-generation quantum sensing, which leverages phenomena such as superposition and entanglement, thereby offering measurement sensitivities far surpassing classical methods. In our discussion, we emphasize its potential to revolutionize various scientific and technological domains. Starting with a foundational overview of quantum sensors, distinguishing them from quantum computing and communication technologies, we then highlight the relative maturity of quantum sensing, especially in room-temperature operations, which positions it closest to market adoption. The main part of the monograph is dedicated to solid-state defects, particularly nitrogen-vacancy (NV) centers in diamond, which have emerged as promising candidates for scalable quantum sensors. The unique optical and spin properties of NV centers are explored in detail, emphasizing their possible applications in fields such as biomedical imaging, materials science, and semiconductor inspection. We delve into the technical aspects of integrating NV centers with conventional electronic and photonic systems, discussing the challenges and innovations in electronic interface circuits, photonic integration, and system-level integration technologies. Additionally, we examine gas-based quantum sensors, particularly those utilizing Rydberg atoms, which offer high precision due to their long coherence times. The challenges of integrating gas-based sensors, compared to their solid-state counterparts, are also briefly discussed. Overall, the monograph underscores the potential of second-generation quantum sensors, particularly those based on NV centers, to be the first scalable, high-volume quantum devices on the market, with applications spanning various fields due to their high sensitivity and room-temperature operation.
This paper explores the potential of quantum sensors for achieving quantum precision measurement. The core claim is that leveraging the inherent properties of quantum sensors, specifically quantum effects like tunneling and entanglement, can enable significantly more accurate measurements of physical quantities compared to classical techniques. This work outlines the fundamental principles and theoretical frameworks underpinning this approach, focusing on the mechanisms by which quantum sensors achieve this enhanced precision. We examine various quantum sensor modalities, including SQUID magnetometers, atomic clocks, and NV centers, and discuss the challenges and future directions in this burgeoning field. The primary objective is to demonstrate how quantum measurement, exploiting the principles of quantum mechanics, can surpass the limitations imposed by classical measurement methodologies. The discussion includes a review of relevant theoretical concepts and a conceptual framework for understanding the relationship between sensor design, quantum effects, and measurement precision. Ultimately, this paper aims to provide a foundational understanding of the transformative potential of quantum sensing for precision measurement applications.