Progress in Quantum Electronics最新文献

Unlocking the vast potential of optical sensing technology has long been hindered by the challenges of achieving fast, sensitive, and broadband photodetection at ambient temperatures. In this review, we summarize recent progress in the study of nonlinear photocurrent in topological quantum materials, and its application in broadband photodetection without the use of p–n junction based semiconductor diodes. The intrinsic quadratic transverse current-input voltage relation is used to rectify the alternating electric field from incident radio, terahertz or infrared waves into a direct current, without a bias voltage and at zero magnetic field. We review novel photocurrents in several material systems, including topological Weyl semimetals, chiral crystals, ferroelectric materials, and low dimensional topological insulators. These quantum materials hold tremendous promise for broadband high-frequency rectification and photo-detection, featuring substantial responsivity and detectivity.

Weak-value amplification (WVA) is a metrological protocol that effectively amplifies ultra-small physical effects, making it highly applicable in the fields of quantum sensing and metrology. However, the amplification effect is achieved through post-selection, which leads to a significant decrease in signal intensity. Consequently, there is a heated debate regarding the trade-off between the amplification effect and the success probability of post-selection, questioning whether WVA surpasses conventional measurement (CM) in terms of measurement precision. Extensive research indicates that the specific theoretical assumptions and experimental conditions play crucial roles in determining the respective advantages of WVA and CM. WVA provides new perspectives for recognizing the important role of post-selection in precision metrology. It demonstrates significant advantages in two aspects: (i) WVA based on the phase space interaction provides feasible strategies to practically achieve the Heisenberg-scaling precision using only classical resources. (ii) WVA exhibits robustness against certain types of technical noise and imperfections of detectors. Moreover, WVA allows for various modifications to extend the applicable scope and enhance the metrological performance in corresponding situations. Despite substantial progress in recent years, the inherent connection between the advantages of WVA and its unique features remains incompletely understood. In this paper, we systematically review the recent advances in the WVA scheme, with a particular focus on the ultimate precision of WVA under diverse conditions. Our objective is to provide a comprehensive perspective on the benefits of WVA in precision measurement and facilitate the realization of its full potential.

Interference, which refers to the phenomenon associated with the superposition of waves, has played a crucial role in the advancement of physics and finds a wide range of applications in physical and engineering measurements. Interferometers are experimental setups designed to observe and manipulate interference. With the development of technology, many quantum interferometers have been discovered and have become cornerstone tools in the field of quantum physics. Quantum interferometers not only explore the nature of the quantum world but also have extensive applications in quantum information technology, such as quantum communication, quantum computing, and quantum measurement. In this review, we analyze and summarize three typical quantum interferometers: the Hong–Ou–Mandel (HOM) interferometer, the N00N state interferometer, and the Franson interferometer. We focus on the principles and applications of these three interferometers. In the principles section, we present the theoretical models for these interferometers, including single-mode theory and multi-mode theory. In the applications section, we review the applications of these interferometers in quantum communication, computation, and measurement. We hope that this review article will promote the development of quantum interference in both fundamental science and practical engineering applications.

The minimalistic design of InGaN-based MQW microdisk lasers based on whispering gallery mode (WGM) resonances has been attracting research interests in recent years. To compete with the prevalent InGaN-based VCSELs and edge-emitters, microdisk lasers must demonstrate superior performance under electrical injection. Yet, the challenges in the shift from initial optically pumped investigations to studies centered on electrically injected microdisk lasers has posed a barrier to successful commercialization.

Probing the optical and charge transport characteristics in molecular junctions not only provides fundamental understanding of light–matter interactions and quantum transport at the atomic and molecular scale, but also holds great promise for the development of molecular-scale optical and electronic devices. Herein, an overview of recent progress in fabricating and characterizing photoswitching molecular systems using both the current measured from single molecule circuits as well as the light signals monitored in photodetectors is presented. We review four groups of azobenzene, diarylethene, dihydroazulene, spiropyran photoswitching molecules that have been used to construct photoswitching molecular devices by scanning tunneling microscope-based or mechanically controlled break-junction techniques, focusing on the impact of light-induced reactions on the charge transport processes at the single molecule level. We also discuss key optical properties of photoswitching systems, uncovered by a range of optical methods including transient absorption and ultrafast spectroscopies, that are critically related to structural symmetry or nonlinear optical effects.

Advanced laser methods have recently been used in human and animal head tissues for functional and molecular imaging. Combining these approaches with various probes and nanostructures gives up a new path for theranostic applications in brain tissues. The diverse optical properties of head tissues such as the scalp, skull, cerebrospinal fluid, and brain tissues result in considerable photon scattering and absorption. Diffusion of photons inside head tissues decreases the optical imaging quality and limits the optical resolutions of cellular and neural treatments. Tissue optical clearing (TOC) was set up more than a century ago to make tissue transparent by immersing it in liquids with a matching RI as the tissue. This approach has lately gained popularity in the field of brain imaging. The physical fundamentals of optical clearing (OC) procedures for brain tissue, such as RI matching with chemical agents, dehydration, delipidation, decalcification, hyperhydration, and innovative hybrid brain OC methods, are explored here. This study covers critical issues such as choosing the best brain OC methods and optimizing wavelength and laser energy to control tissue optical properties. Here, innovative ways for decreasing photon scattering based on immersion procedures and induced heating tunnels are discussed. In addition, simulation methods of photon migration in brain tissues (based on random approaches) are investigated, paving the way for the proper brain OC strategy. Finally, the limitations of this method for in vivo applications are discussed, as well as possible applications in cranial implants, optogenetics, laser brain stimulation, and functional optical imaging.

Miniaturized and rationally assembled nanostructures exhibit extraordinarily distinct physical properties beyond their individual units. This review will focus on structured small-scale optical cavities, especially on plasmonic nanoparticle lattices that show unique electromagnetic near fields from collective optical coupling. By harnessing different material systems and structural designs, various light-matter interactions can be engineered, such as nanoscale lasing, nonlinear optics, and exciton-polariton coupling. Key device performance of nanoscale lasers will be discussed, including low power threshold, output tunability, and electrical pump. This review will also cover emerging applications of nanoscale optical cavities in quantum engineering. Structured nanoscale cavities can serve as a scalable platform for integrated photonic circuits and hybrid quantum photonic systems.