Optical light-matter interaction drives a vast array of innovative sensing applications, pushing the boundaries of industrial technological advancement. This overview highlights our on-going research efforts at the intersection of fundamental science and industrial application. Specifically, we present recent progress in: (a) the identification of levitated charged nanoparticles via optical spectroscopy in a Paul trap; (b) high-sensitivity magnetic field measurements using electromagnetically induced transparency (EIT) in a room-temperature alkali vapor.
Optical light-matter interaction drives a vast array of innovative sensing applications, pushing the boundaries of industrial technological advancement. This overview highlights our on-going research efforts at the intersection of fundamental science and industrial application. Specifically, we present recent progress in: (a) the identification of levitated charged nanoparticles via optical spectroscopy in a Paul trap; (b) high-sensitivity magnetic field measurements using electromagnetically induced transparency (EIT) in a room-temperature alkali vapor.
While the fundamental principles of light-matter interaction are well-understood and drive countless technologies, the world of multiphoton processes remains a fascinating puzzle, holding the potential to drastically alter our understanding of how light interacts with matter at its most basic level. This rich interplay of light and matter unveils novel phenomena that can be harnessed for sensing with exceptional precision, as exemplified by multiphoton quantum sensing. This thesis delves into the applications of multiphoton quantum protocols, particularly in imaging, communication, and plasmonic sensing, to surpass classical limitations and achieve enhanced sensitivity. We explore the potential of multiphoton quantum processes, particularly in the nanoscale regime and within subsystems of macroscopic systems, where novel and ultra-sensitive sensing methodologies emerge. Subsequent chapters of this thesis demonstrate the transformative potential of multiphoton quantum sensing, elucidating the design, implementation, and experimental results of specific sensing protocols tailored to diverse applications. Our analysis combines experimental observations and theoretical predictions to assess the sensitivity and performance of these protocols. Additionally, the thesis discusses potential future directions and advancements in the field, envisioning applications in biomolecule detection, environmental monitoring, and fundamental studies of light-matter interactions at the nanoscale. Concluding reflections highlight the implications of multiphoton quantum sensing across scientific disciplines and lay the groundwork for future research endeavors.
Quantum-enhanced sensing has emerged as a transformative technology with the potential to surpass classical sensing modalities in precision and sensitivity.This study explores the advancements and applications of quantum-enhanced sensing, emphasizing its capacity to bridge fundamental physics and practical implementations.The current progress in experimental demonstrations of quantum-enhanced sensing systems was reviewed, focusing on breakthroughs in metrology and the development of physically realizable sensor architectures.Two practical implementations of quantum-enhanced sensors based on trapped ions were proposed.The first design utilizes Ramsey interferometry with spin-squeezed atomic ensembles, employing laser-induced spin-exchange interactions to reconstruct the sensing Hamiltonian.This approach enables measurement rates to scale with the number of sensing atoms, achieving sensitivity enhancements beyond the standard quantum limit (SQL).The second implementation introduces mean-field interactions mediated by coupled optical cavities that share coherent atomic probes, enabling the realization of high-performance sensing systems.Both sensor systems were demonstrated to be feasible on state-ofthe-art ion-trap platforms, offering promising benchmarks for future applications in metrology and imaging.Particular attention was given to the integration of quantum-enhanced sensing with complementary imaging technologies, which continues to gain traction in medical imaging and other fields.The mutual reinforcement of quantum and complementary technologies is increasingly supported by significant investments from governmental, academic, and commercial entities.The ongoing pursuit of improved measurement resolution and imaging fidelity underscores the interdependence of these innovations, advancing the transition of quantum-enhanced sensing from fundamental research to widespread practical use.
While the fundamental principles of light-matter interaction are well-understood and drive countless technologies, the world of multiphoton processes remains a fascinating puzzle, holding the potential to drastically alter our understanding of how light interacts with matter at its most basic level [1–4]. This rich interplay of light and matter unveils novel phenomena that can be harnessed for sensing with exceptional precision, as exemplified by multiphoton quantum sensing. This thesis delves into the applications of multiphoton quantum protocols, particularly in imaging, communication, and plasmonic sensing, to surpass classical limitations and achieve enhanced sensitivity. We explore the potential of multiphoton quantum processes, particularly in the nanoscale regime and within subsystems of macroscopic systems, where novel and ultra-sensitive sensing methodologies emerge. Subsequent chapters of this thesis demonstrate the transformative potential of multiphoton quantum sensing, elucidating the design, implementation, and experimental results of specific sensing protocols tailored to diverse applications. Our analysis combines experimental observations and theoretical predictions to assess the sensitivity and performance of these protocols. Additionally, the thesis discusses potential future directions and advancements in the field, envisioning applications in biomolecule detection, environmental monitoring, and fundamental studies of light-matter interactions at the nanoscale. Concluding reflections highlight the implications of multiphoton quantum sensing across scientific disciplines and lay the groundwork for future research endeavors.
Quantum sensing is a paradigm shift in measurement science. It uses the intrinsic quantum properties of particles and their wave functions, such as superposition, entanglement, and coherence, to achieve unparalleled sensitivity, precision, and miniaturization. This paper provides a practical engineering perspective on quantum sensing, linking foundational quantum principles to real-world applications. It reviews key enabling technologies, such as single-photon detectors, which can detect individual photons with high efficiency and low noise; nitrogen vacancy (NV) centers in diamonds, which sense nanoscale magnetic and electric fields at room temperature; and Rydberg atoms, which detect precise electromagnetic fields using optical techniques. Additionally, we examine the integration of quantum sensing approaches with optical fiber systems, high-lighting advances in distributed sensing capabilities enabled by quantum detectors. The discussion emphasizes the advantages of quantum measurement techniques over classical methods. Finally, it outlines the emerging domain of quantum sensing applications and the ongoing miniaturization and cost reduction of quantum devices, demonstrating their potential to transform multiple scientific and industrial fields.
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 behavior of multilevel atomic ensembles (e.g., alkali-metal atoms) can be influenced significantly by the intensity of a driving field (or controlling/coupling field). The phase coherence between two transition pathways driven by a probe light and a driving field can lead to the effect known as electromagnetically induced transparency (EIT). In EIT, the probe light can pass through a three-level alkali-metal atomic vapor without absorption or reflection when two coherent resonances (transition pathways driven by the driving and probe fields) are present and the linewidths of the transparency windows are sufficiently narrow. The optical characteristics of atomic systems can also be affected by the Doppler broadening of the absorption profile in a spectroscope. Our analysis indicates that both broadenings (related to the transitions excited by the driving and probe fields) can be expanded, leading to an increase in the transmittance and reflectance broadenings when a coupling field with adaptive strength is applied; the corresponding temperature would, thus, be implemented and readable. We show that the most suitable preparation for temperature sensing via an EIT vapor is to provide 80 times the spontaneous decay rate (SDR) of the excited atomic levels. This configuration results in reflectance and transmittance values that range between zero and one and cover a temperature range of 0 K to 600 K. As an example, we demonstrate the integration of specialized coating technologies with EIT ensembles for temperature sensing in the range of dozens of kelvins at and above room temperature. A key advantage of this temperature-sensing system is its ability to use adaptive resonant visible light as the probe field. This novel approach may find applications in providing unprecedented levels of precision and control in temperature sensing for coating processes and in the design of other photonic or optical devices. It can also be used to determine the temperature-dependent behavior of the specific heat of alkali-metal solids and gases (including the latent heats of vaporization or sublimation of alkali-metal solids) through the reflection and transmission spectra of the vaporized EIT atomic vapors.