Field Of Quantum Technologies Research Articles

Enhanced optical pumping using mutually orthogonal magnetic fields for quantum sensing

The atomic population trapped in irrelevant atomic states is a limiting factor for sensors based on laser-atom interaction. Using a bi-chromatic light field along with a specific combination of magnetic fields, we show a significant increase in the amplitude (i.e., more than seven times) of a two-photon coherent population trapping (CPT) resonance, which can be effectively used for atomic magnetometry. This increase in amplitude can be explained through enhanced optical pumping via the transfer of population to the relevant Zeeman states. Our experimental observations are consistent with the theoretical calculations carried out for a realistic three-level atomic system using density matrix formalism. We further discuss the optimum condition for enhanced optical pumping by adjusting the ground-state decoherence rate. Enhanced optical pumping through the manipulation of the magnetic field is quite important and is of great interest in the field of quantum technology.

A graduate laboratory experiment to set up a photon-counting detector using MKIDs

This paper presents a new laboratory activity aimed at developing knowledge and expertise in microwave applications at cryogenic temperatures. The experience focuses on the detection of infrared photons through microwave kinetic inductance detectors. The experimental setup, theoretical concepts, and activities involved are detailed, highlighting the skills and knowledge gained through the experience. This experiment is designed for graduate students in the field of quantum technologies.

Floquet-Rydberg quantum simulator for confinement in Z2 gauge theories

Recent advances in the field of quantum technologies have opened up the road for the realization of small-scale quantum simulators of lattice gauge theories which, among other goals, aim at improving our understanding on the nonperturbative mechanisms underlying the confinement of quarks. In this work, considering periodically driven arrays of Rydberg atoms in a tweezer ladder geometry, we devise a scalable Floquet scheme for the quantum simulation of the real-time dynamics in a Z2 LGT, in which hardcore bosons/spinless fermions are coupled to dynamical gauge fields. Resorting to an external magnetic field to tune the angular dependence of the Rydberg dipolar interactions, and by a suitable tuning of the driving parameters, we manage to suppress the main gauge-violating terms and show that an observation of gauge-invariant confinement dynamics in the Floquet-Rydberg setup is at reach of current experimental techniques. Depending on the lattice size, we present a thorough numerical test of the validity of this scheme using either exact diagonalization or matrix-product-state algorithms for the periodically modulated real-time dynamics. Published by the American Physical Society 2024

Impact of quantum technologies on innovation processes in the global economy

The article examines the impact of quantum technologies on innovation processes in the global economy. It analyzes the critical aspects of integrating quantum technologies in various sectors of the economy, particularly in the financial, health care, production, and IT spheres. Theoretical models and empirical data confirming how quantum technologies can accelerate innovation processes, increase research efficiency, and create new economic opportunities are considered. The article also provides practical recommendations for strategic planning and management of innovation processes in the conditions of the quantum revolution. Special attention is paid to the importance of an interdisciplinary approach and cooperation between business and the state. The author noted that the modern economy is on the threshold of a new era, where quantum technologies play a decisive role, which represents a new class of tools capable of radically changing traditional approaches to data processing, security, and computing. Quantum computers, quantum cryptography and quantum communication open opportunities for the economy that can accelerate the development of new materials, optimize logistics chains and increase the level of data security. At the same time, the article highlights the need to develop global standards in the field of quantum technologies. The results of the research will contribute to a better understanding of the potential of quantum technologies to stimulate innovation and increase the competitiveness of the economy. Keywords: quantum technologies, global economy, innovation processes, quantum cryptography, quantum computing, quantum modeling, quantum communication, economic models, quantum algorithms, cyber security, logistics optimization, risk management, economic growth, financial markets, health care, production, quantum networks, development strategies, digital economy, technological revolution.

Tunable magnetic anisotropy of Os-Ru dimer on 2D transition metal chalcogenides substrates

The precise manipulation of atoms enables the creation of distinct materials from the bottom up to construct devices with breakthrough performance, especially in the field of quantum technologies. A large magnetic anisotropy energy (MAE) is important to realize bit storage of information in magnetic memory devices. As the smallest magnetic nanostructure, substrate-supported transition metal dimers are potential atomic-scale storage medium to obtain large MAEs. Using high-throughput first-principles calculations, we have performed a systematic investigation of the MAE of 76 heterodimensional systems consisting of zero-dimensional Os-Ru dimer and experimentally synthesized two-dimensional transition metal dichalcogenides (TMDs). Huge MAEs in the range of 102.09–247.69 meV were found in 13 of these heterodimensional systems. In particular, the Os-Ru@T-ZrSe2 with the largest MAE of 247.69 meV corresponds to a theoretical blocking temperature (67 K) in terms of a relaxation time of 10 years and a storage density of 281 Tb·inch−2. The underlying mechanism for the significant enhancement of MAE is attributed to the rearrangement of the in-plane molecular orbitals near the Fermi level, which is closed relative to the electron transfer capability between the Os-Ru dimer and the TMD substrates. In addition, we have also constructed a heat map for TMD-supported Os-Ru dimer, showing the degree of correlation between MAEs and feature descriptors. Our work not only suggests an effective way to improve MAE of transition metal dimers but also extracts relatively simple rules for substrate selection.

Assessing the journey of technology hype in the field of quantum technology

The ‘second quantum revolution’ promises new technologies enabled by quantum physics and has been the subject of substantial hype. We show that while creating expectations has helped secure support for quantum research, their iterative effects can come to affect the field in concrete ways. These iterative impacts for quantum include emerging discussions about ethics and the delivery of promised outcomes. Such contestations could open up alternative quantum futures, but this will depend on how the ‘hype helix’ of iterative expectations unfolds.

Quantum in Consumer Technology

Reports on the field of quantum technology, a rapidly developing industry that has the potential to revolutionize a wide range of industries, including consumer technology. One of the most exciting current applications of quantum technology in the consumer industry is the area of quantum computing. Quantum computers use quantum bits, or qubits, instead of classical bits, which allows them to perform certain calculations much faster than traditional computers. This has the potential to greatly improve fields such as machine learning, drug discovery, financial modeling, and cryptography.. Quantum technology is a rapidly developing field that has the potential to revolutionize a wide range of industries, including consumer technology. Current applications include quantum computing and quantum encryption, while future use cases include quantum sensors and quantum teleportation. Shortly, it is expected that more and more companies will begin to use quantum computing to improve their products and services. This includes companies in a wide range of industries, including finance, healthcare, and technology. As technology continues to evolve, it will be exciting to see how it will change the way we live and interact with technology.

Quantum random number generation based on a perovskite light emitting diode

The recent development of perovskite light emitting diodes (PeLEDs) has the potential to revolutionize the fields of optical communication and lighting devices, due to their simplicity of fabrication and outstanding optical properties. Here we demonstrate that PeLEDs can also be used in the field of quantum technologies by implementing a highly-secure quantum random number generator (QRNG). Modern QRNGs that certify their privacy are posed to replace classical random number generators in applications such as encryption and gambling, and therefore need to be cheap, fast and with integration capabilities. Using a compact metal-halide PeLED source, we generate random numbers, which are certified to be secure against an eavesdropper, following the quantum measurement-device-independent scenario. The obtained generation rate of more than 10 Mbit s−1, which is already comparable to commercial devices, shows that PeLEDs can work as high-quality light sources for quantum information tasks, thus opening up future applications in quantum technologies.

On-Chip 3D Printing of Polymer Waveguide-Coupled Single-Photon Emitter Based on Colloidal Quantum Dots.

In the field of quantum technology, there has been a growing interest in fully integrated systems that employ single photons due to their potential for high performance and scalability. Here, a simple method is demonstrated for creating on-chip 3D printed polymer waveguide-coupled single-photon emitters based on colloidal quantum dots (QDs). By using a simple low-one photon absorption technique, we were able to create a 3D polymeric crossed-arc waveguide structure with a bright QD on top. These waveguides can conduct both excitation laser and emitted single photons, which facilitates the characterization of single-photon signals at different outputs with a conventional confocal scanning system. To optimize the guiding effect of the polymeric waveguide structures, comprehensive 3D finite-difference time-domain simulations were performed. Our method provides a straightforward and cost-effective way to integrate high-performance single-photon sources with on-chip photonic devices, enabling scalable and versatile quantum photonic circuits for various applications.

Global innovation and competition in quantum technology, viewed through the lens of patents and artificial intelligence

In this work we elucidate international trends in the field of quantum technology (QT) by analysing a global patent database built from an operational definition of QT that was generated through the curated application of artificial intelligence (AI). In doing so, we demonstrate how the sophisticated use of intellectual property information, enhanced by the artful deployment of AI techniques, may produce more reliable and useful revelations for policymakers and managers about global innovation in emerging fields of technology than is possible through conventional methods of data collection and analysis. We also demonstrate the utility of this approach for reliably characterising the evolving constituent sub-fields of QT. By adopting a hybrid human-AI approach to both the definition and the analysis of QT, we have produced some novel insights about global innovation and national organisational profiles in the QT field, particularly concerning dynamic competition between the USA and China.

Thermal self-oscillations in monolayer graphene coupled to a superconducting microwave cavity

Nonlinear phenomena in superconducting resonator circuits are of great significance in the field of quantum technology. We observe thermal self-oscillations in a monolayer graphene flake coupled to molybdenum–rhenium superconducting resonator. The graphene flake forms a SINIS junction coupled to the resonator with strong temperature dependent resistance. In certain conditions of pump power and frequency, this nonlinearity leads to thermal self-oscillations appearing as sidebands in cavity transmission measurements with strong temperature dependence and gate tunability. The experimental observations fit well with theoretical model based on thermal instability. The modelling of the oscillation sidebands provides a method to evaluate electron phonon coupling in disordered graphene sample at low energies.

The Legal Nature of Quantum Communications

The article discusses legal issues related to quantum communications. Special attention is paid to the principles on which the work of quantum communications is based. The necessity of observing the uniformity of the conceptual apparatus in the system of Russian law is pointed out. The review and comparison of the main strategic planning acts of the European Union, the Russian Federation and other countries in the field of quantum technologies and quantum communications is given. The main foreign and international standards are analyzed. Considerable attention is paid to the attempt to give the concept of quantum communications as an information technology, which can be fixed in the adopted acts. The main legal problems associated with the introduction of quantum communications are identified. The conclusion is made about the negative consequences of excessive regulation of this area.

Epitaxial Growth of Planar Hutwires on Silicon‐on‐Insulator Substrates

Quantum devices based on holes confined in crystalline Ge nanostructures have emerged as a promising platform in the field of quantum technology. Epitaxial Ge hutwires (HWs) successfully used in pioneering quantum bit (qubit) experiments are the logical next choice for long-distance coherent spin–spin coupling experiments. However, leakage currents are currently limiting the device performance of HWs on bulk Si substrates. This drawback can be mitigated by the HW growth on silicon-on-insulator (SOI) substrates. Herein, molecular beam epitaxy (MBE) HW growth developed on technologically relevant SOI substrates with different device layer thicknesses is shown. Using atomic force microscopy characterization, the fabrication of HWs on SOI with lengths of up to 600 nm is demonstrated. In addition, the very narrow window of growth parameters for which successful HW growth can be achieved and the distinct differences of HW growth on SOI versus bulk Si substrates are addressed.

On the Development of the Scientific Base of Quantum Technologies

The purpose of the article is to study the development of research in the field of quantum technologies, based on a bibliometric analysis of publications indexed in databases from the Web of Science Core Collection from 1990 to 2020. The global output of publications, the productivity of individual countries and organizations, indicators of international scientific cooperation are considered. The characteristic features of world studies in the field are revealed: a high concentration in the group of leaders, a noticeable participation of corporations and military scientific structures, and growing international cooperation. Considerable attention is paid to the positions of Russia, which towards the end of the period returned to the top ten countries in terms of productivity. The Russian Academy of Sciences is the sixth among the world scientific organizations in the production of publications on quantum technologies for the entire period; Russian scientists actively cooperate with foreign scientists, including those from leading Western countries. The internal landscape is characterized by a significant predominance of the “Center”, where the country’s leading research institutes and universities are located, and the still small research contribution of the Russian commercial sector.

Coupled Optical Solitons in Microwave-Assisted Plasmonic Graphene Waveguide

The emergence of soliton in plasmonic graphene waveguide is investigated in the presence of optical and microwave fields. The considered configuration encompasses a monolayer graphene waveguide placed between parallel plate capacitor. The optical fields are launched as surface plasmon polariton modes, while the microwave field is applied to the capacitor. The governing nonlinear-Schrödinger equations of the propagating optical fields have been derived. It is shown that electronically controlled coupled optical solitons can be achieved by altering the corresponding self- (and cross-) modulation terms with proper electrical biasing and doping concentration. This present work paves the way towards soliton formation in the field of quantum technology.

Low loss optical structure for directional and efficient photon emission using nitrogen-vacancy center in diamond

Nitrogen-vacancy center in diamond based photonic structures are appealing in the field of quantum technology as they offer single photon emission with an efficient directional output beam. In this paper, we report a nano-range waveguide design which is capable of producing ~70% photon collection efficiency with a NA of 1. We have utilized the pyramidal diamond structure onto a rectangular diamond substrate with the NV center positioned on top surface of this optical structure. A stable and directional emission of a far field pattern is achieved even with a wide range of dipole positions. Less power coupling inside the optimized device helps to enhance the efficiency near NV emission spectra. This optical waveguide can be employed in various applications in the NV based magnetometers and quantum devices

Quantum entanglement in the lab

The recent and rapid progress in the field of quantum technologies stimulates developments of specific courses and experimental training for future engineers and scientists. We describe below the experimental setup developed at Institut d’Optique Graduate School for engineering and Master students. During a labwork session afternoon, students can study a source of polarization entangled state pairs of photons and perform an experimental violation of Bell’s inequalities. This emblematic experiment is one of the experiments dedicated to quantum photonics. It was built in 2005 in the LEnsE (the Laboratoire d’Enseignement Experimental) of the Institut d’Optique Graduate School and has been perfectly working for almost eighteen years already.

Bibliometric Analysis in the Field of Quantum Technology

The second quantum technological revolution started around 1980 with the control of single quantum particles and their interaction on an individual basis. These experimental achievements enabled physicists, engineers, and computer scientists to utilize long-known quantum features—especially superposition and entanglement of single quantum states—for a whole range of practical applications. We use a publication set of 54,598 papers from Web of Science, published between 1980 and 2018, to investigate the time development of four main subfields of quantum technology in terms of numbers and shares of publications, as well as the occurrence of topics and their relation to the 25 top contributing countries. Three successive time periods are distinguished in the analyses by their short doubling times in relation to the whole Web of Science. The periods can be characterized by the publication of pioneering works, the exploration of research topics, and the maturing of quantum technology, respectively. Compared to the USA, China’s contribution to the worldwide publication output is overproportionate, but not in the segment of highly cited papers.

Quantum Simulations with Superconducting Networks

The importance of a scientific discovery sometimes is also reflected in the impact it has in the most diverse situations. The discovery of the Josephson effect has been of fundamental importance in so many different areas, from fundamental to applied science and technology. More recently, it is also playing a pivotal role also in the emerging field of quantum technologies. In this brief note I would like to highlight the importance of the Josephson effect in the realisation of quantum simulators.

Security of the decoy state method for quantum key distribution

Quantum cryptography or, more precisely, quantum key distribution (QKD), is one of the advanced areas in the field of quantum technologies. The confidentiality of keys distributed with the use of QKD protocols is guaranteed by the fundamental laws of quantum mechanics. This paper is devoted to the decoy state method, a countermeasure against vulnerabilities caused by the use of coherent states of light for QKD protocols whose security is proved under the assumption of single-photon states. We give a formal security proof of the decoy state method against all possible attacks. We compare two widely known attacks on multiphoton pulses: photon-number splitting and beam splitting. Finally, we discuss the equivalence of polarization and phase coding.