Quantum sensors have attained unrivaled sensitivities that enable fundamental discoveries and quantum technologies, but they are prone to instability and decoherence via external influences. Exploiting feedback between quantum sensors, the authors present a combinatorial device in which a second quantum system more sensitive to external perturbations is used to stabilize a primary sensor. This approach would use $e.g.$ both nuclear and electronic spins in diamond to build a stable quantum gyroscope, allowing navigation without GPS. More broadly, this work demonstrates the advantage of colocating a quantum sensor to steady other quantum devices, rather than using bulky classical gear.
Quantum sensors have attained unrivaled sensitivities that enable fundamental discoveries and quantum technologies, but they are prone to instability and decoherence via external influences. Exploiting feedback between quantum sensors, the authors present a combinatorial device in which a second quantum system more sensitive to external perturbations is used to stabilize a primary sensor. This approach would use e.g. both nuclear and electronic spins in diamond to build a stable quantum gyroscope, allowing navigation without GPS. More broadly, this work demonstrates the advantage of colocating a quantum sensor to steady other quantum devices, rather than using bulky classical gear.
Gyroscopes find wide applications in everyday life from navigation and inertial sensing to rotation sensors in hand-held devices and automobiles. Current devices, based on either atomic or solid-state systems, impose a choice between long-time stability and high sensitivity in a miniaturized system. Here, we introduce a quantum sensor that overcomes these limitations by providing a sensitive and stable three-axis gyroscope in the solid state. We achieve high sensitivity by exploiting the long coherence time of the 14N nuclear spin associated with the nitrogen-vacancy center in diamond, combined with the efficient polarization and measurement of its electronic spin. Although the gyroscope is based on a simple Ramsey interferometry scheme, we use coherent control of the quantum sensor to improve its coherence time and robustness against long-time drifts. Such a sensor can achieve a sensitivity of $\ensuremath{\eta}\ensuremath{\sim}0.5\phantom{\rule{0.28em}{0ex}}(\mathrm{mdeg}\phantom{\rule{0.16em}{0ex}}{\mathrm{s}}^{\ensuremath{-}1})/\sqrt{\mathrm{Hz}\phantom{\rule{0.16em}{0ex}}{\mathrm{mm}}^{3}}$ while offering enhanced stability in a small footprint. In addition, we exploit the four axes of delocalization of the nitrogen-vacancy center to measure not only the rate of rotation, but also its direction, thus obtaining a compact three-axis gyroscope.
Gyroscopes find wide applications in everyday life from navigation and inertial sensing to rotation sensors in hand-held devices and automobiles. Current devices, based on either atomic or solid-state systems, typically impose a choice between long-time stability and high sensitivity in a miniaturized system. Thanks to their optical properties, nuclear spins associated with NV centers in diamond have been proposed to overcome this challenge. While optical polarization improves these devices' sensitivities, further improvement is needed. Here, we propose a gyroscope protocol based on a two-spin system that includes a spin intrinsically tied to the host material, while the other spin is effectively in an inertial frame. The rotation rate is then extracted by measuring the relative rotation angle between the two spins starting from their population states, which are robust against spin dephasing. Importantly, the relative rotation rate between the two spins is enhanced by their hyperfine coupling by more than an order of magnitude, further boosting the achievable sensitivity. The ultimate sensitivity of the gyroscope is limited by the lifetime of the spin system and is compatible with a broad dynamic range, even in the presence of magnetic noises or control errors due to initialization and qubit manipulations. Our result enables precise measurement of slow rotations and exploration of fundamental physics.
We propose to implement a solid-state rotation sensor by employing a many-body quantum spin system which takes the advantages of the easy controllability of the electron spin and the robustness provided by the collective nuclear spin state. The sensor consists of a central electron spin coupled to many surrounding nuclear spins. Previously, this central spin system has been suggested to realize a quantum memory. Here, we further utilize the collective nuclear spins, which store a certain quantum state, to detect the macroscopic rotation. Different from other nuclear spin-based gyroscopes, our proposal does not directly manipulate nuclear spins via nuclear magnetic resonance technique. We analytically and numerically investigate the effects of partial nuclear polarization and decoherence on the sensitivity. We also briefly introduce the procedure to generate entanglement between nuclear spins through the quantum memory technique and to utilize this entanglement to enhance the sensing performance. Our proposal paves the way to the experimental realization of a compact solid-state, full-electrical, and spin-based gyroscope.
The extreme sensitivity of quantum systems towards the external perturbations and in the same time their ability to be strongly coupled to the measured target field makes them to be stable under the environmental noise. A high quality quantum sensor can be engineered even on the platform of a single trapped qubit. There is a variety of optimal and sub-optimal algorithms for effective control over the quantum system states. Here we discuss the opportunity to improve the efficiency of the external field quantum sensor based on a single qubit via its feedback tracking.
Modern developments have led to a breakthrough in quantum technology that is the key to improving navigation and positioning systems. Translation of concepts such as superposition, entanglement, and quantum interference into quantum sensors pave the way toward high precision and accuracy in measuring gravitational, magnetic, and inertial forces. This chapter provides information on the performance of quantum sensors emphasizing navigation and positioning techniques. The superior performance of quantum accelerometers, gyroscopes, and magnetometers regarding sensitivity, non-drift, and lower errors are compared to classical systems. In addition, the implementation of quantum sensors in systems that can work alone, and in systems that are incorporated with classical GPS systems but have added quantum advantages is explained. This work also discusses the current research and development efforts on quantum sensors, the challenges of integrating them into modern applications, approaches to miniaturizing the technology for practical use, and their potential future adoption in areas such as creature design, autonomous transportation, defense, and aerospace. As a result of the comprehensive content included in this chapter, readers will gain a sufficient appreciation of the scientific principles upon which quantum sensors are anchored, as well as technology’s capability and versatility in enabling accurate navigation and positioning.
Abstract The inherent vulnerability of Global Navigation Satellite Systems (GNSS) to interference, spoofing, and signal degradation highlights the urgent need for robust augmentation and alternative solutions to support resilient Positioning, Navigation, and Timing (PNT) services. Among emerging technologies, quantum sensing stands out for its ability to harness fundamental quantum phenomena, such as superposition and entanglement, enabling absolute, drift-free and ultra-sensitive measurements of inertial forces, gravity, and magnetic fields with long-term stability and reduced dependency on external signals. This capability offers a promising pathway to enhance positioning and navigation performance in GNSS-denied or GNSS-contested environments. Here, we present a comprehensive review of quantum sensing technologies in the context of positioning and navigation, including cold atom interferometry, atomic vapour cell, superconducting quantum interference devices, and room temperature solid-state systems like nitrogen-vacancy centres in diamond, and their potential to support positioning and navigation across a range of operational contexts. Both standalone and hybrid quantum-classical architectures are examined, with case studies illustrating their ability to reduce navigation drift and achieve sub-metre accuracy through quantum-enhanced inertial navigation, gravity-aided positioning, and magnetic field-matching approach. Despite their promise, challenges including decoherence, environmental robustness, miniaturisation, and integration complexity remain significant barriers to practical deployment. Rather than replacing existing classical systems, quantum sensors are best served as complementary solutions within multi-layered PNT frameworks. This review also identifies priorities for advancing field-deployable quantum positioning and navigation solutions, including sensor robustness, miniaturisation, seamless integration, and the development of protocols to quantify quantum performance. Aligned with international quantum initiatives, this work contributes to the vision of secure, interference-resistant navigation infrastructure for scientific, industrial, and defence applications.