bluuebunny/crossref_metadata_2025 huggingface dataset:
The Questionable Middle Class
Authors: Baas Michiel
Published: September 2024

This article examines what the idea of a new or changing India signifies in the way it is experienced from a middle-class perspective. While the often-used adjectives of lower, new, and upper in terms of middle-class belonging seem to indicate economic difference, the article argues that it is more productive to think of this hierarchical structuring as primarily sociocultural in nature. The way studies have attempted to capture the size of the middle class offers important insight here. This article draws upon long-term fieldwork among lower or new middle-class men who hail from vernacular backgrounds and who are employed as fitness trainers in India. The gym floor not only offers an opportunity to make money but also to acquire sociocultural capital through interactions with clients. The upward mobility this facilitates, in which the men's own muscular bodies are key, underscores the porousness as well as the rigidity of middle-class boundaries.
From the establishment of a national bioinformatics society to the development of a national bioinformatics infrastructure
Authors: Mirăuță Bogdan , Zenoaga-Barbăroșie Cătălina , Abrudan Monica , Mihășan Marius , Giurgiu Mădălina , Mihalachi Daria , Lazăr Michalis-Daniel ,   RSBI Members, Banciu Horia L.
Published: September 2024

We describe the evolution of a bioinformatics national capacity from scattered professionals into a collaborative organisation, and advancements in the adoption of the bioinformatics infrastructure philosophy by the national community. The Romanian Society of Bioinformatics (RSBI), a national professional society, was founded in 2019 to accelerate the development of Romanian bioinformatics. Incrementally, RSBI expanded its role to include: i) developing a community and engaging the public and stakeholders, ii) a national training approach, including through increased interactions with European training resources, and iii) advocating national participation in European bioinformatics infrastructures. In a next step RSBI led the development of the national bioinformatics infrastructure, the Romanian Bioinformatics Cluster (CRB) with the mission to act as an ELIXIR National Node. In this paper we report both the successful projects in training, public engagement, and policy projects, as well as initiatives related to data federation that, while not successful, can serve as valuable learning experiences for future implementations. We explain CRB’s structure and the role such an entity can play in the national bioinformatics infrastructure for data, tools, and training. Finally, we offer insights into the evolving role of the bioinformatics professional society and the synergies and interactions with the National ELIXIR Node
EXAMINATION OF THE USE OF TERMINOLOGICAL DEFINITIONS IN THE FIELD OF DIGITAL EMPLOYMENT
Authors: Lagutina E. , Mahmutova K. , Ryzhikova M. , Koneva D.
Published: September 2024

The relevance of the topic presented by the authors is determined by the state of the labor market in the context of the dynamics of modern socio-economic life of society. Developments in technology have made it possible to work using various digital services. This is changing both the nature of work and the way people are employed. The situation of «staff shortage», recognized by both employers and the state, sets the course for the increasingly widespread introduction of digital employment. This article attempts to define a combination of concepts in the field of digital employment for further research. The authors conducted a content analysis of the popularity of the use of terms in the field of digital employment by Internet users. The results of the work can be used as a basis for developing tools for conducting sociological surveys in the field of digital employment.
DEVELOPMENT OF CORPORATE CULTURE IN THE PUBLISHING ACTIVITY OF THE UNIVERSITY: THE CASE OF THE URFU NAMED AFTER THE FIRST PRESIDENT OF RUSSIA B.N. YELTSIN
Authors: Lysenko E. , Plotnikova I.
Published: September 2024

The development of corporate culture is an important component of the organization and personnel management activities in conditions of uncertainty and challenges of the external environment. As part of the celebration of the anniversary of the UrFU editorial and publishing division, corporate culture events were developed and implemented aimed at developing communications in the professional field, finding solutions to existing problems, increasing awareness in the university environment, improving activities, etc. The article presents an assessment of the activities carried out in the field of publishing in the higher education environment. In the course of the study, carried out in accordance with a special program and using mixed, quantitative and qualitative methods, the results reflecting the impact of anniversary events of corporate culture on the activities of the publishing department of the university were obtained. The need for the implementation of participatory management as a way of developing corporate culture in the editorial and publishing department of a large federal university of Russia has been identified.
Physicochemical and Sensory Characteristics of Instant Pumpkin Soup with Variations of Porang Flour as a Thickener
Authors: N Nurrahman , Suyanto Agus , Ayuningtyas Rr Annisa , Yonata Diode
Published: September 2024

Pumpkin (Cucurbita moschata) can be processed into instant soup. However, the weakness is its low viscosity. Porang flour as a thickening agent is expected to improve the shortcomings of instant pumpkin soup. This study aimed to investigate the effect of porang flour addition on the physical and sensory characteristics of instant pumpkin soup. This study used a non-factorial, completely randomized design, where the concentration of porang flour (0; 0.5; 1; 1.5 and 2%) was the independent variable. The result showed that the addition of porang flour caused an increase in moisture content, dietary fiber, viscosity, water solubility index and water absorption index in instant pumpkin soup. However, there was a decrease in the value of water activity, vitamin E, rehydration ratio, color, and sensory characteristics of instant pumpkin soup. In conclusion, adding 0.5% porang flour is recommended to produce instant pumpkin soup with good sensory and physicochemical properties.
Biopreservation of Food Using Probiotics: Approaches and Challenges
Authors: Rameez K. V. Muhammed , Santhoshkumar P. , Yoha K. S. , Moses J. A.
Published: September 2024

Food preservation has received a paramount focus throughout history, prompting the use of various methods such as chemical additives, thermal treatments, and nonthermal approaches to prolong the shelf life of food. In this regard, biopreservation is emerging as a promising alternative owing to its eco-friendly nature and minimal toxicity effects. It involves harnessing natural microorganisms and their byproducts to enhance both the nutritional value and longevity of food products. This review delves into the role of probiotics and postbiotics in biopreservation, elucidating their beneficial impact on human health and their potential as ‘safe’ food preservatives. It covers a spectrum of pro/post-biotic organisms, including bacteria and yeast, alongside different types of biopreservatives, their mechanisms of action, and applications across diverse food categories. Furthermore, the review assesses the influence of biopreservation on food quality and sensory attributes. However, commercialization hurdles loom, particularly concerning safety and regulatory compliance, necessitating thorough scrutiny before widespread implementation.
Design and experimental validation of an aspheric multi-lenticular plano-convex lens for VCSEL beam collimation
Authors: Madeniyeti Naerzhuoli , Yi Zihan , Ge Aiming , Zhao Hui , Qiu Jian , Liu Kefu
Published: September 2024

In this work, we propose a design method of an aspheric lens that achieves collimation for a VCSEL laser beam. The designed lens features a planar front surface and an aspheric back surface of which the profile is mathematically characterized and precisely determined based on the proposed method. The method is derived from a basic geometric-optics analysis and construction approach. The collimating effect of the lens was first analyzed in simulation and then validated in experimental measurement. The experimental results show that the collimator lens transforms the input VCSEL laser beam divergence angle from 25° (436.33 mrad) to an output angle of 3.6906 mrad.
Influence of anisotropic factor fluctuations on the scintillation index in optical turbulence
Authors: Xie Jinyu , Zheng Jiancheng , Bai Lu , Jia Heming
Published: September 2024

Atmospheric turbulence results in the degradation of performance in optical communications, with the scintillation phenomenon significantly influencing the optical link performance. Various physical parameters influence optical scintillation, such as the atmospheric refractive index structure constant, optical transmission distance, turbulence intensity, and anisotropy. In classical theoretical predictions, the anisotropic factor is often assumed to be constant over the long term. Nevertheless, anisotropic factors in real turbulence undergo temporal fluctuations, manifesting as a distribution. Consequently, it is imperative to examine the correlation between the distribution of anisotropic factors and the outcomes of scintillation. This study utilizes a semi-Gaussian distribution for sampling anisotropic factors and employs the non-Kolmogorov spectrum to develop scintillation theory for Gaussian beams in the transition region from weak to strong turbulence. The results indicate that the scintillation index may be higher than the theoretical prediction when considering the distribution of anisotropic factors in weak turbulence. Conversely, in strong turbulence, the scintillation index may be lower than the theoretical prediction, necessitating further judgment for moderate to strong turbulence.
Light-injection attack against practical continuous-variable measurement-device-independent quantum key distribution systems
Authors: Wang Yiliang , Zheng Yi , Fang Chenlei , Shi Haobin , Pan Wei
Published: September 2024

Continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) can defend all detection-side attacks effectively. Therefore, the source side is the final battlefield for performing quantum hacking attacks. This paper investigates the practical security of a CV-MDI QKD system under a light-injection attack. Here, we first describe two different light-injection attacks, i.e., the induced-photorefractive attack and the strong-power injection attack. Then, we consider three attack cases where Eve only attacks one of the parties or both parties of the CV-MDI QKD system. Based on the analysis of the parameter estimation, we find that the legitimate communication parties will overestimate the secret key rate of the system under the effect of a light-injection attack. This opens a security loophole for Eve to successfully obtain secret key information in a practical CV-MDI QKD system. In particular, compared to the laser-damage attack, the above attacks use a lower power of injected light and have a more serious effect on the security of the system. To eliminate the above effects, we can enhance the practical security of the system by doping the lithium niobate material with various impurities or by using protective devices, such as optical isolators, circulators, optical power limiters, and narrow-band filters. Apart from these, we can also use an intensity monitor or a photodetector to detect the light-injection attack.
Cavity-dumped femtosecond Yb:CALYO laser based on SESAM assisted Kerr-lens mode locking
Authors: Yu Yang , Ba Biao , Tian Wenlong , Wang Geyang , Tong Hui , Su Yulong , Wei Zhiyi , Xu Xiaodong , Zhu Jiangfeng
Published: September 2024

In this paper, we present the demonstration of a cavity-dumped Kerr-lens mode-locked femtosecond oscillator based on an Yb:CALYO crystal for the first time. With the assistance of an SESAM, the Kerr-lens mode-locked Yb:CALYO laser delivered pulses with an average power of 2.8 W at a repetition rate of 61.3 MHz, corresponding to a pulse energy of 45.6 nJ. By employing a Pockels Cell consisting of dual β-BBO crystals and a thin film polarizer for cavity dumping, laser pulses of 280 nJ were achieved at both 1 MHz and 10 kHz repetition rates. The shortest pulse duration measured was 233 fs without external compression, resulting in a peak power of 1.06 MW.
PbS-based SWIR micro-spectrometer with on-chip Fabry–Perot filter array
Authors: Li Taipeng , Mu Ge , Hao Qun , Tang Xin
Published: September 2024

Miniaturized and portable on-chip spectrometers have been widely explored to facilitate many applications including chemical analysis, environmental monitoring, medical diagnostics, and astronomical observations. However, the optical spectra of micro-spectrometers are mostly within the visible range. Here, we develop high-performance short-wave infrared (SWIR) micro-spectrometers through the integration of wafer-scale uniform lead sulfide (PbS) thin films with an on-chip Fabry–Perot filter array. The optoelectronic performance of PbS-based detectors could be markedly improved through the optimization of chemical bath deposition (CBD) conditions. The high-sensitivity PbS detectors based on the Fabry–Perot filter array demonstrate chemical analysis application.
Characterizing third-order intermodulation distortion of photodetectors based on de-coupling and de-embedding modulation distortion of modulators
Authors: Lei Di , Xu Ying , Zou Xinhai , Zhang Yali , Zhang Zhiyao , Li Linze , Chen Baile , Zhang Shangjian , Liu Yong , Zhu Ninghua
Published: September 2024

A novel, to the best of our knowledge, electro-optical modulation method is proposed for measuring third-order intermodulation distortion of photodetectors (PDs) based on de-coupling and de-embedding modulation distortion of modulators. The method utilizes dual parallel intensity modulation to generate electro-optical stimulus signals with fast and fine sweeping capability, and it eliminates the nonlinear impact of modulators by using low-frequency bias swing, allowing a direct extraction of the third-order output intercept point (OIP3) of PD from the combined nonlinear response contributed by both the modulators and the PD. The OIP3 of PD is frequency-swept measured with our method and compared to those with the conventional method to check for consistency. The proposed method enables a modulator-distortion-free, fast, and fine sweeping measurement of PDs using a simple system.
Enhanced cone-shaped lasing from cholesteric liquid crystals
Authors: Chanishvili Andro , Chubinidze Ketevan , Petriashvili Gia , Ponjavidze Nino , Wardosanidze Zurab , Zurabishvili Tsisana
Published: September 2024

Strong conical lasing in the violet–blue range of the spectrum from dye doped cholesteric liquid crystals is obtained. In contrast to the previously reported cases, the cone laser emission is sharply increased at the local maximums of the luminescence peaks of the dyes. Besides that, for obtaining the cone lasing strong focusing of the pumping beam is not required. Extremely low pump density is achieved for the cholesteric liquid crystal lasers. It is important that the cone lasing can be observed without simultaneous manifestation of any other laser emissions.
Mathieu ray-wave structured light with self-healing elliptical accelerating vortices
Authors: Wei Wenjun , Tang Miaomiao , Zhang Hao , Tai Yuping , Shen Yijie , Li Xinzhong
Published: September 2024

Ray-wave structured vortex beams have attracted increasing attention due to their unique spatial geometric coupling to control complex orbital angular momentum (OAM). Still, current models were constrained by circular symmetry with limited modulation freedom. Herein, we propose a generalized class of ray-wave light fields called Mathieu geometric modes (MGMs) fulfilling the form of a stationary coherent state but based on a set of helical Mathieu modes (HMMs), in which geometrically tunable elliptical accelerating vortices are obtained by tuning their eccentricity-related parameters. MGMs also possess intriguing properties of coordinate transformation, self-healing, and multilayer tunable angular acceleration upon propagation. MGMs have higher degrees of freedom to control spatial accelerating vortices, paving the way for higher-dimensional optical tweezers and complex particle manipulation.
SNR analysis of a multi-channel temporal correlation scheme in quantum-enhanced target detection
Authors: Wang Weihao , Li Jun , Wei Rongyu , Guo Jihong , Guo Qinghua
Published: September 2024

In lossy and noisy environments, quantum-enhanced target detection based on temporal quantum correlation encounters low signal-to-noise ratio (SNR), resulting in poor detection performance. To address these challenges, we propose a multi-channel temporal correlation scheme. In this scheme, signal photons from multiple independent entangled sources illuminate the target and arrive at the same detector. Coincidences are obtained by correlation measurements of the entangled photons on one signal path and different reference paths. We then propose a weighted average processing method for fusing the coincidences to obtain higher SNR. The relationship between the SNR and the number of sources is analyzed for different background noise levels. It is shown that the SNR increases as the number of sources increases, but eventually approaches a limit. Experimental results verify the correction of our theoretical analysis.
Observation of modulation instability in a coherently driven active fiber ring resonator at 2 μm wavelength
Authors: Bartnick Moritz , Negrini Stefano , Brès Camille-Sophie , Mussot Arnaud
Published: September 2024

We report the first, to our knowledge, observation of the nonlinear phenomenon known as modulation instability (MI) in a coherently driven fiber resonator pumped at 1972 nm. To compensate for the very high losses in this spectral region, we have integrated a thulium-doped fiber amplifier inside the cavity. Lower losses allow a lower MI threshold, leading to the observation of this phenomenon at a moderate input power. The results align closely with the numerical simulations of the system. Our study shows that active compensation of loss can be implemented in the 2 µm wavelength range to construct fiber ring cavities with high finesse. It paves the way to the observation of more complex nonlinear effects optical frequency comb through cavity soliton generation.
Terahertz quasi-optics imaging systems with easy zoom based on beam-shaping devices and a freeform lens
Authors: Ma Xinru , Hu Hao , Wang Xiaolei
Published: September 2024

Terahertz (THz) waves show outstanding application value in the nondestructive detection of hidden targets that are impenetrable to visible light. However, the uncertain location of hidden targets puts a higher demand on the zoom function of the THz quasi-optical systems, especially when the object is immovable. This paper proposes a continuous zoom system working in the THz band consisting of a negative axicon disk, a segmented axicon, and a freeform lens. The negative axicon disk and segmented axicon shape THz waves into annular beams with adjustable diameters, which are respectively focused at different positions by the zone-designed freeform lens. Both simulation and experimental results indicate that the zoom range of the system can reach 82 mm while maintaining an imaging resolution of 6 mm. Notably, continuous zooming is achieved by merely rotating the negative axicon disk, instead of the lens moving. Moreover, all devices in the system can be fabricated by 3D printing or machining. This approach offers the advantages of simple adjustment and low cost, providing, to our knowledge, a novel perspective for the design and application of THz quasi-optical imaging systems.
Pre-compensating digital-to-analog converter impairments with an LSTM neural network
Authors: Imtiaz Hamza , Zheng Zibo , Nejad Rizan Homayoun , Rusch Leslie A. , Zeng Ming
Published: September 2024

The performance of high-speed coherent communication heavily depends on digital-to-analog converters (DACs) when they operate within bandlimited and nonlinear regimes. We examine neural network (NN) based digital pre-distortion (DPD) methods to compensate the memory effects that are intertwined with the nonlinear response of the DAC. Using a long short-term memory (LSTM) NN architecture, we examine 8-level amplitude shift keying (ASK-8) at 64 Gbaud. We demonstrate experimental improvements of 1.6 dB and 2 dB in signal-to-noise ratio (SNR) compared to the Volterra and linear solutions, respectively.
Strong interactions between integrated microresonators and alkali atomic vapors: towards single-atom, single-photon operation
Authors: Zektzer Roy , Lu Xiyuan , Hoang Khoi Tuan , Shrestha Rahul , Austin Sharoon , Zhou Feng , Chanana Ashish , Holland Glenn , Westly Daron , Lett Paul , Gorshkov Alexey V. , Srinivasan Kartik
Published: September 2024

Cavity quantum electrodynamics (cQED), the interaction of a two-level system with a high quality factor (Q) cavity, is a foundational building block in different architectures for quantum computation, communication, and metrology. The strong interaction between the atom and the cavity enables single-photon operation, which is required for quantum gates and sources. Cold atoms, quantum dots, and color centers in crystals are among the systems that have shown single-photon operations, but they require significant physical infrastructure. Atomic vapors, on the other hand, require limited experimental infrastructure and are hence much easier to deploy outside a laboratory, but they consist of an ensemble of moving atoms that results in short interaction times involving multiple atoms, which can hamper quantum operations. A solution to this issue can be found in nanophotonic cavities, where the optical mode is confined to a small volume and light-matter interaction is enhanced, so that fast single-atom, single-photon operations are enabled. In this work, we study the interaction of an atomically clad microring resonator (ACMRR) with different-sized ensembles of Rb atoms. We demonstrate strong coupling between an ensemble of ≈50 atoms interacting with a high quality factor (Q=4.3×105) ACMRR, yielding a many-atom cooperativity C=(5.5±0.3). We continue to observe signatures of atom-photon interaction for a few (<3) atoms, for which we observe saturation at the level of a few intracavity photons. Further development of our platform, which includes integrated thermo-optic heaters to enable cavity tuning and stabilization, should enable the observation of interactions between single photons and single atoms.
High-Rate Photon-Number Resolved Detection with Transition-Edge Sensors Enabled by Machine Learning
Authors: Li Zhenghao , Kendall Matthew J.H. , Zhu Ruidi , Mer Ewan , Yu Shang , Walmsley Ian A. , Patel Raj B.
Published: September 2024

We report a machine-learning-based algorithm that allows transition-edge sensors to distinguish photon number traces at a repetition rate that overcomes their slow recovery time. Detector tomography is performed to benchmark the algorithm’s performance.
Certification of quantum non-Guassian photon coincidences through lossy channels
Authors: Checchinato Riccardo , Littmann Jan-Heinrich , Lachman Lukáš , Lee Jaewon , Höfling Sven , Schneider Christian , Filip Radim , Predojević Ana
Published: September 2024

Quantum non-Gaussianity is a stricter criterion and the next step after non-classicality in the classification of quantum states. We will present our experimental results on the certification of quantum non-Gaussian coincidences through a noisy channel.
Cavity-Quantum Electrodynamics with Single Diamond Tin-Vacancy Centers
Authors: Herrmann Yanik , Fischer Julius , Brevoord Julia M. , Sauerzapf Colin , Wienhoven Leonardo G. C. , Feije Laurens J. , Pasini Matteo , Eschen Martin , Ruf Maximilian , Weaver Matthew J. , Hanson Ronald
Published: September 2024

We show diamond Tin-Vacancy centers, coherently-coupled to a tunable microcavity. The exceptional optical properties of this emitter in combination with a stable, high quality cavity enables a cavity transmission signal modulated by a single emitter.
Hong-Ou-Mandel interference of two photons of vastly different color
Authors: Mann Felix , Chrzanowski Helen M. , Gewers Felipe , Plack Marlon , Ramelow Sven
Published: September 2024

Hong-Ou-Mandel interference is a quantum phenomenon that underlies quantum information processing with single photons. Using a quantum frequency converter as an active beam splitter we demonstrate Hong-Ou-Mandel interference of two photons of vastly different colors.
Continuous microwave to optical conversion and detection based on warm Rydberg atoms
Authors: Mazelanik Mateusz , Borówka Sebastian , Wasilewski Wojciech , Parniak Michał
Published: September 2024

We demonstrate a wideband continuous microwave-to-optical conversion scheme based on a warm atomic system. The scheme enables counting microwave pho-tons with 57dB dynamic range, reaching 4K thermal radiation limit, and allows all-optical phase-sensitive detection of weak microwave fields.
Scalable electronic control of trapped-ion qubits
Authors: Malinowski Maciej , Allcock David T. C. , Srinivas Raghavendra , Löschnauer Clemens M. , Hughes Amy C. , Nourshargh Rustin , Negnevitsky Vlad , King Steven A. , Matthiesen Clemens , Harty Thomas P. , Ballance Christopher J.
Published: September 2024

One of the most formidable challenges of scaling up quantum computers is that of control-signal delivery. In this Paper, we present the recent results on integrated and scalable control of trapped-ion qubits at Oxford Ionics.
Direct Detection of Quantum Superposition at a Distance
Authors: Kun Daniel , Strömberg Teodor , Spagnolo Michele , Rozema Lee A. , Walther Philip
Published: September 2024

Employing an XOR game, we verify quantum superposition with local measurements only, consisting of photon-counting and coincidence detection and using a second, indistinguishable photon as a shared resource, without the need to re-interfere the superposition.
Two-Photon Emission and Correlations in Hybrid Superconductor-Semiconductor Devices
Authors: Bouscher Shlomi , Buchbinder Sima , Panna Dmitry , Balasubramanian Krishna , Jacovi Ronen , Kumar Ankit , Schneider Christian , Höfling Sven , Hayat Alex
Published: September 2024

We experimentally demonstrated two-photon emission in GaAs/AlGaAs superconducting light emitting diodes (SLEDs), observing EL spectra and g(2) photon correlations corresponding to Cooper-pair recombination. We utilized a superlattice structure and transparent superconducting contacts to enhance pair emission.
Real-time Quantum Random Number Generation with Integrated Photonics: Robustness and Scalability for Industrial Deployment
Authors: Marangon D. G. , Smith P. R. , Walk N. , Paraiso T. K. , Dynes J. F. , Lovic V. , Sanzaro M. , Roger T. , de Marco I. , Lucamarini M. , Yuan Z. L. , Shields A. J.
Published: September 2024

We present a fast, scalable quantum random number generator using integrated photonics on an electronic platform. It operates continuously at gigahertz rates, with minimal variations, and achieves secure 2 Gbit/s generation in an uncontrolled environment.
Multiplexed Quantum Secret Sharing via subspace encoding
Authors: Cabrejo-Ponce Meritxell , Spiess Christopher , Sevilla Carlos , Steinlechner Fabian
Published: September 2024

By manipulating the spectral phase of polarization-entangled photons, we show a subspace encoding method that enables Quantum Secret Sharing to be deployed in multiplexed and reconfigurable networks.
Distribution of Telecom Time-Bin Entangled Photons through a 7.7 km Antiresonant Hollow-Core Fiber
Authors: Antesberger Michael , Richter Carla M. D. , Poletti Francesco , Slavík Radan , Petropoulos Periklis , Hübel Hannes , Trenti Alessandro , Walther Philip , Rozema Lee A.
Published: September 2024

We show that hollow-core fibers have emerged for quantum technology by distributing entangled time-bin qubits over a 7.7 km fiber. We study this fiber’s advantages in transmission speed and dispersion over a broad spectral range.
Development of Mode-Hop Free Tunable Chip-Scale Laser at 780 nm for Nonlinear Quantum Photonics and Atomic Sensing
Authors: Castro Joshua , Nolasco-Martinez Eber , Pintus Paolo , Zhang Zeyu , Shen Boqiang , Morin Theodore , Thiel Lillian , Steiner Trevor J. , Lewis Nicholas , Patel Sahil , Bowers John E. , Weld David M. , Moody Galan
Published: September 2024

We present III-V-on-Si3N4 chip-scale lasers operating from 765-795 nm with < 5 kHz intrinsic linewidth and > 100 GHz mode-hop-free tuning. We demonstrate their application for nonlinear photonics with Si3N4 microring resonators, atomic spectroscopy, and locking to 87Rb.
Compact Vertical-External-Cavity Surface-Emitting Laser (VECSEL) Platform for Quantum Technology
Authors: Penttinen Jussi-Pekka , Kantola Emmi , Uusitalo Topi , Ranta Sanna , Hietalahti Arttu , Vuohenkunnas Roope , Guina Mircea
Published: September 2024

VECSELs have recently gained a preferential position as an enabling solution for the development of scientific and industrial quantum technology systems utilizing ions, atoms, and molecules. Here we report a compact VECSEL-system (VXLTM) exhibiting a unique combination of features addressing quantum technology applications. Recent experiments demonstrating new capability for frequency locking, linewidth narrowing to sub-Hz level, and wavelength coverage are presented.
Quantum paraelectric parametric amplifiers
Authors: Ulrich Anja , Brahim Kamal , Boelen Andries , Kuyken Bart , Haffner Christian
Published: September 2024

A conceptual analysis of an RF parametric amplifier based on the quantum paraelectric strontium titanate. The analysis suggests a gain of 20dB, a bandwidth of several MHz and a dynamic range of -60dBm are feasible.
Continuous Polarization Correction for Long-distance Quantum Key Distribution
Authors: Chandrashekara Uday , Kržič Andrej , Gómez Rodrigo , Steinlechner Fabian
Published: September 2024

We present a polarization correction module using a beacon laser. Using this device we stabilize the polarization drift of a 70km dark fiber link used for quantum communication.
Enhancing Quantum Communications: Automated, Ultra-Bright Entangled Photon Generation
Authors: Sebak Rana , Gomez Rodrigo , Gamarra Sara Montano , Tafur Julio , Beckert Erik , Steinlechner Fabian
Published: September 2024

We've developed a compact, efficient entangled photon source using time-reversed Hong-Ou-Mandel interference, with motorized alignment for robust space applications. This innovation promises to advance quantum communications by ensuring high-quality, accessible quantum technologies.
Higher-dimensional HOM effect with directionally unbiased linear-optical multiports enables entangled state routing in quantum networks
Authors: Schwarze Christopher , Simon David S. , Manni Anthony , Ndao Abdoulaye , Sergienko Alexander V.
Published: September 2024

A four-port beamsplitter only maps between two input and output modes. We introduce a more general four-port scatterer that supports a broader class of state transformations, enabling a higher-dimensional HOM effect and entangled state routing.
Generation and distribution of entangled time-bin qubits
Authors: Moon Kiwon , Kim Jinwoo , Kim Guhwan , Park Jiho , Slusar Tetiana , Kim Hong-seok , Kim Jintae , Park Jaegyu , Kim Min-su , Ju Jung Jin
Published: September 2024

In this work, we present the generation and the distribution of controllable time-bin qubits over 100 km single-mode fiber. Moreover, we briefly show our entanglement source based on a nonlinear photonic integrated circuit platform.
Optical Fractional Fourier Transform in the time-frequency domain based on a quantum memory
Authors: Niewelt Bartosz , Jastrzębski Marcin , Kurzyna Stanisław , Nowosielski Jan , Wasilewski Wojciech , Mazelanik Mateusz , Parniak Michał
Published: September 2024

Operations in the time-frequency domain of light are widely used in communication. Transformations such as fractional Fourier transform are indispensable tool for noise reduction. We present a protocol for quantum memories to perform this operation.
Optical and Spin Coherence of NV centers in Isotopically Purified Diamond for Quantum Networks
Authors: van Ommen Hendrik B. , Schymik Kai-Niklas , Yamamoto Takashi , Taminiau Tim H.
Published: September 2024

We discuss measurements on single NV centers in isotopically purified diamond and show coherent optical transitions combined with enhanced electron and carbon spin coherence. These results open avenues for new quantum network applications.
What is the best wavelength for fibre quantum communication?
Authors: Clark Marcus J. , Yang Ruizhi , Wang Rui , Nejabati Reza , Simeonidou Dimitra , Joshi Siddarth K.
Published: September 2024

We present a detailed simulation study to conclusively answer the wide spread debate in the quantum community about the benefits of using the telecommunications C-Band or O-Band for quantum communication.
Integrated Preparation of Qubit States and Chip-Fibre Interface for Quantum Networks
Authors: Zatsch Jonas , Engling Tim , Huster Jeldrik , Hauser Nico , Schweikert Christian , Barz Stefanie
Published: September 2024

We present an integrated photonic chip, which offers the on-chip control of a path-encoded qubit. It has the capability of converting the quantum state to polarization-encoding, enabling a chip-fibre interface for quantum network tasks.
Reconstruction of Generic Light Pulses Stored via EIT using the Coherent Atomic Transfer Function
Authors: DeLuca Billie V. , Patnaik Anil K.
Published: September 2024

We use the Fourier-based coherent atomic transfer (CAT) function for EIT storage in a Λ atomic system to reconstruct an arbitrary pulse shape given the retrieved output using numerical deconvolution algorithms.
Classical Attack on Bell Inequalities
Authors: Guha Aishi , Davis Noah A. , La Cour Brian R.
Published: September 2024

Representing multi-mode squeezed light with a Gaussian random vector, our locally deterministic detection model challenges the CHSH game, achieving fidelities exceeding 96%. Squeezing strength, detector threshold, and efficiency influence the security of the quantum bound.
Mode entanglement created by interacting superradiant emitters
Authors: Mechel Chen , Tziperman Offek , Gorlach Alexey , Kaminer Ido
Published: September 2024

We show that interacting quantum emitters coupled to a waveguide or any bath of optical-modes emit mode-entangled light. Controlling this entanglement could create useful multi-mode pure states, although each mode has thermal statistics.
Photon Number Filtering using Dynamically Coupled Cavities
Authors: Pedersen Kamma Nørrelund , Bundgaard-Nielsen Matias , Kristensen Philip Trøst , Heuck Mikkel
Published: September 2024

We numerically investigate using dynamically coupled nonlinear cavities to modify the photon number of incident optical pulses. By optimizing the instantaneous coupling rate, we convert a coherent state to a single-photon with over 99% efficiency.
Decreasing critical detection efficiency via parallelized Bell tests
Authors: Sabogal Daniel R. , Goel Suraj , Valencia Natalia Herrera , Cabello Adán , Malik Mehul
Published: September 2024

We present the experimental implementation of three parallelized Bell tests encoded in an eight-dimensional entangled state that allows for the reduction of the critical detection efficiency relevant to loophole-free Bell experiments.
Environmental Testing of the Dual Wavelength QKD Payload for a CubeSatellite
Authors: Zhang Peide , Sagar Jaya , Willett Hobbs , Joshi Siddarth , Rarity John
Published: September 2024

Cube-satellites promise a flexible platform for global scale QKD but limited SWaP leads to design challenges. We present a payload engineering module for the UK SPOQC mission highlighting low volume and high key rate.
Noise characterization for co-propagation of classical and CV-QKD signals over fiber and free-space link
Authors: Frazão João dos Reis , van Vliet Vincent , Gümüş Kadir , van den Hout Menno , van der Heide Sjoerd , Albores-Mejia Aaron , Škorić Boris , Okonkwo Chigo
Published: September 2024

Real-time CV-QKD receiver achieves peak 2.9 Mbit/s secret-key-rates over 12.8 km of fiber, while co-propagating 15 classical channels, separated 1 nm from the quantum signal. Performance degrades at higher launch powers due to crosstalk.
Experimental Demonstration of a Hybrid Authenticated Key Exchange Integrating QKD and PQC in a Single Protocol
Authors: Garms Lydia , Paraiso Taofiq , Hanley Neil , Khalid Ayesha , Rafferty Ciara , Shields Andrew , Cid Carlos , O’Neill Maire
Published: September 2024

Currently deployed public-key infrastructure faces an imminent threat in the face of quantum computers. It is expected that, given sufficiently large and reliable quantum computers, dedicated quantum algorithms such as Shor's algorithm [1] will completely break cryptographic schemes whose security is based on the discrete logarithm and integer factorisation problems. This includes widely deployed cryptographic algorithms such as RSA, Diffie-Hellman and elliptic-curve based approaches which underpin the security of existing electronic communications. Therefore, the secrecy of highly sensitive information currently being exchanged is under significant threat as messages can be recorded in bulk and decrypted in the future in so-called harvest-and-decrypt attacks.
Large-Scale Fiber Interferometry to Measure the Gravitationally Induced Phase Shift on Entangled Photons
Authors: Polini Eleonora , Macri Dorotea , Yin Xinghui , Oelker Eric , Chruściel Piotr , Dvali Georgi , Hilweg Christopher , Hudelist Mario , Mago Dorilian Lopez , Mieling Thomas , Morling Thomas , Oancea Marius , Silvestri Raffaele , Steininger Florian , Yu Haocun , Walther Philip , Mavalvala Nergis
Published: September 2024

Gravitational time dilation, a prediction of General Relativity, lacks confirmation alongside quantum mechanics. Our experiment aims to measure gravitationally induced phase shift of path-entangled photons between two vertically displaced arms of a fiber interferometer.
Quantum enhanced precision metrology for quantum networks
Authors: Jabir M. V. , Dawkins Riley , Sabines-Chesterking J. , Reddy Dileep V. , Lita A. E. , Battou A. , Gerrits Thomas
Published: September 2024

We construct a source generating two-mode squeezed vacuum states for precise transmission estimation. Experimentally, we demonstrate that measurements using TMSV states offer greater quantum advantage compared to coherent states.
Quantum Sensing with arrays of NV centers for High Energy Physics
Authors: Dreyer Cyrus , Lopez-Morales Gabriel , Linden Steven , Salter Patrick , Zajac Joanna M
Published: September 2024

We propose, model theoretically, build and test a dark matter detector facilitating an array of laser written NV centers in diamond. Theoretical simulation and experiments using confocal microscopy allow us to demonstrate proof-of-principle device operation.
Detection of Organic Gases in Air via Quantum Fourier-Transform Mid-Infrared Spectroscopy
Authors: Neves Simon , Kartiyasa Adimulya , Ghosh Shayantani , Gaulier Geoffrey , La Volpe Luca , Wolf Jean-Pierre
Published: September 2024

A Quantum FTIR spectrometer was used to detect, discriminate and track organic gases in ambient air with unprecedented sensitivity, leveraging spectral entanglement, induced coherence, long-path absorption, and specific analysis techniques such as DOAS.
Optical beam shaping for robust quantum inertial sensors
Authors: Fuchs Ulrike , Schlutow Henrike , Baptista Joel Gomes , Sidorenkov Leonid A. , Janvier Camille
Published: September 2024

Inertial sensors based on atom interferometry benefit from laser beams of homogeneous intensity and wavefront. We present a fiber-coupled athermalized beam shaper retaining these properties over an extended temperature range, for a field-deployed quantum gravimetry.
Bell State Statistics with Post-Selection Loophole
Authors: Lanham S. Andrew , La Cour Brian R.
Published: September 2024

We demonstrate a classical post-selection-induced violation of a Bell-type inequality using the setup of Q. Zhang et al., Phys. Rev. A 77, 062316 (2008). The results demonstrate how post-selection alone can cause Bell inequality violations.
Directionally-unbiased Linear Multiports: Quantum Interference and Registration of Multi-Dimensional Rotation
Authors: Simon D. S. , Schwarze C. R. , Sergienko A. V.
Published: September 2024

We describe a quantum walk in which photons remain clustered together as they walk along a chain. This effect can be used to construct higher-dimensional quantum Sagnac interferometers that measure rotaƟons about three axes simultaneously.
All-fiber microendoscopic polarization sensing at single-photon level aided by deep-learning
Authors: Bielak Martin , Vašinka Dominik , Ježek Miroslav
Published: September 2024

We address the problem of precise polarization measurement in challenging conditions. To resolve this problem, we introduce a single-shot all-fiber method based on intermodal interaction aided by deep-learning, providing accuracy down to a single-photon level.
Graph states for robust quantum magnetometry in noisy environments
Authors: Nguyen Phu Trong , Le Trung Kien , Nguyen Hung Q. , Ho Le Bin
Published: September 2024

This study examines how symmetric graph-state resources can improve quantum magnetometry under Markovian and non-Markovian noise. It shows significant improvements in estimating Larmor frequencies, indicating the potential for enhanced magnetic field measurements in noisy environments.
Approaching maximal precision of Hong-Ou-Mandel interferometry with non-perfect visibility
Authors: Meskine O. , Descamps E. , Keller A. , Lemaître A. , Baboux F. , Ducci S. , Milman P.
Published: September 2024

This work explores precision limits in two-photon Hong-Ou-Mandel interferometry under non-perfect visibility. A theoretical model is developed and experimentally validated. Results show a 0.97 ratio between experimental precision and the quantum limit, setting a new benchmark.
Continuous Variable Distributed Quantum Sensing in Integrated Photonics
Authors: Puzio Bethany , Ferranti Giacomo , Tasker Joel , Frazer Jonathan , Matthews Jonathan C. F.
Published: September 2024

We present plans for performing continuous variable distributed quantum sensing on a silicon photonic chip. Linear functions of four integrated phase shifters will be measured with entanglement enhanced precision.
Optimization of Entangled Two-Photon Absorption Experiments based on Semi-Empirical Approach with Accessible Chemical Properties of Fluorescence Dyes
Authors: Gäbler Tobias B. , Krstić Aleksa , Jain Nitish , Gili Valerio F. , Saravi Sina , Setzpfandt Frank , Gräfe Markus
Published: September 2024

Studies on entangled two-photon absorption often do not show proof of fluorescence emission. Also, theoretical predictions for specific dyes are missing. We introduce a semi-empirical approach based on accessible chemical properties to optimize experimental investigations.
Spin Squeezing Process for Surface Electrons over Liquid Helium
Authors: Chaudhary Manish
Published: September 2024

In this paper, we analyze the process of the entanglement generation in the spin qubits for electrons floating over liquid Helium. This is achieved by coupling two spins of the electrons with the collective phonon mode of surface vibration. This coupling is useful in realizing Mølmer-Sørensen gate that is used in generating entangled states.
Multipartite Remote Entanglement of Single Rare-earth Ions
Authors: Wu Chun-Ju , Ruskuc Andrei , Green Emanuel , Hermans Sophie , Choi Joonhee , Faraon Andrei
Published: September 2024

We develop protocols that can entangle remote, optically distinguishable qubits in a way that’s robust to optical spectral diffusion. We demonstrate bipartite and tripartite entanglement of single rare-earth ions distributed between two separate nanophotonic cavities.
Remote entanglement between solid-state quantum memories
Authors: Hänni Jonathan , Sebastian Alberto Rodriguez-Moldes , Appas Félicen , Wengerowsky Sören , Teller Markus , Grandi Samuele , de Riedmatten Hugues
Published: September 2024

We report our progress towards the demonstration of telecom-heralded matter-matter entanglement between solid-state, on-demand and remote quantum memories based on rare-earth—doped crystals.
Mid-IR hyperspectral imaging with undetected photons
Authors: Placke Marlon , Lindner Chiara , Mann Felix , Kviatkovsky Inna , Chrzanowski Helen M. , Kühnemann Frank , Ramelow Sven
Published: September 2024

By combining a nonlinear interferometer in imaging-mode with Fourier-transform spectroscopy, we realize broadband mid-infrared hyperspectral acquisition with undetected photons. We demonstrate the novel imaging technique on polymer and bio-tissue samples using only near-infrared silicon-based cameras.
Simultaneous quantum imaging and spectroscopy with undetected photons
Authors: Dosan Vasile-Laurenţiu , Perna Adrià Sansa , Basset Marta Gilaberte , Töpfer Sebastian , de Vries Oliver
Published: September 2024

We report a scheme for simultaneous quantum imaging and spectroscopy with undetected photons for low-cost IR sensing. Using curved mirrors and SPDC spatial filtering, we improve fiber-coupled visibility and minimize optical aberrations and system dimensions.
Spectrally Separable Polarization Entanglement Source for Multiphoton Quantum Networking
Authors: Grayson Michael , Meyer Shawn , Sorensen Daniel , Allgaier Markus , Nardelli Nicholas , Fortier Tara , Reddy Dileep V. , Stevens Martin J. , Mazurek Michael D. , Gopinath Juliet T. , Shalm L. Krister
Published: September 2024

We present an SPDC-based photon pair source utilizing an apodized ppKTP crystal to achieve a near-ideal Schmidt number of 1.0032 ±0.0005, indicating spectrally pure photon pairs, essential for multiphoton quantum communication systems.
A highly pure and efficient source of telecom-compatible single photons based on cavity-enhanced SPDC
Authors: Planas Xavier Barcons , Chrzanowski Helen M. , Messner Leon , Wolters Janik
Published: September 2024

Photonic quantum technologies require highly efficient sources of pure single photons. Utilizing pulsed spontaneous parametric down-conversion in a monolithic cavity, we demonstrate a source of pure single-photons with 85% heralding efficiency.
Spatiotemporal Description of Non-linear Interference Based on Cascaded Spontaneous Parametric Down-Conversion.
Authors: Sevilla-Gutiérrez Carlos , Chauhan Purujit , Steinlechner Fabian
Published: September 2024

We model and experimentally demonstrate the full spatiospectral non-linear interference of cascaded SPDC sources using a spectrally dependent Laguerre-Gaussian basis and an arbitrary mode dependent transformation performed by the optical system.
Photonic quantum networks reveal the nonlocal nature of Bell-local states
Authors: Villegas-Aguilar Luis , Polino Emanuele , Ghafari Farzad , Quintino Marco Túlio , Laverick Kiarn T. , Berkman Ian R. , Rogge Sven , Shalm Lynden K. , Tischler Nora , Cavalcanti Eric G. , Slussarenko Sergei , Pryde Geoff J.
Published: September 2024

Bell nonlocality, a fundamental resource for device-independent technologies like quantum key distribution, is highly susceptible to noise. We experimentally demonstrate that single copies of Bell-local states exhibit nonlocality when integrated into a photonic quantum network.
Fully Programmable Quantum Interference of Squeezed States via Frequency Conversion
Authors: Folge Patrick , Bhattacharjee Abhinandan , Stefszky Michael , Lengeling Sebastian , Ricken Raimund , Brecht Benjamin , Silberhorn Christine
Published: September 2024

We experimentally demonstrate fully programmable interference of multiple squeezed states in a frequency bin network by utilizing a engineered frequency conversion process. This offers a scalable approach towards large multi-port quantum state interferometers.