EPJ Quantum Technology最新文献

{"title":"Single-copy entanglement purification: a robust approach for diverse noise sources","authors":"Sajede Harraz,&nbsp;Shuang Cong","doi":"10.1140/epjqt/s40507-025-00342-5","DOIUrl":"10.1140/epjqt/s40507-025-00342-5","url":null,"abstract":"<div><p>Effectively managing various types of decoherence is crucial for leveraging entanglement in quantum information processing and quantum computing. In this paper, we propose purification circuits that deterministically produce a maximally entangled state from a single copy of an imperfect entangled pair affected by various noise sources. Unlike conventional methods, our approach eliminates the need for multiple copies of the entangled state, pre-purification operations, and imposes no restrictions on the initial entanglement fidelity of the imperfect pair. Our method utilizes ancilla qubits and CNOT gates to address errors from Pauli X and Z (bit flip and phase flip), as well as combinations of these errors that create general mixed entangled states and amplitude-damped entangled states. Our analysis shows that noisy CNOT gates impact fidelity minimally, with only the final two gates being critical. We validate our approach through mathematical analysis and practical implementation in Qiskit, demonstrating its effectiveness and robustness.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00342-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Outcomes from a workshop on a national center for quantum education","authors":"Edwin Barnes,&nbsp;Michael B. Bennett,&nbsp;Alexandra Boltasseva,&nbsp;Victoria Borish,&nbsp;Bennett Brown,&nbsp;Lincoln D. Carr,&nbsp;Russell R. Ceballos,&nbsp;Faith Dukes,&nbsp;Emily W. Easton,&nbsp;Sophia E. Economou,&nbsp;E. E. Edwards,&nbsp;Noah D. Finkelstein,&nbsp;C. Fracchiolla,&nbsp;Diana Franklin,&nbsp;J. K. Freericks,&nbsp;Valerie Goss,&nbsp;Mark Hannum,&nbsp;Nancy Holincheck,&nbsp;Angela M. Kelly,&nbsp;Olivia Lanes,&nbsp;H. J. Lewandowski,&nbsp;Karen Jo Matsler,&nbsp;Emily Mercurio,&nbsp;Inès Montaño,&nbsp;Maajida Murdock,&nbsp;Kiera Peltz,&nbsp;Justin K. Perron,&nbsp;Christopher J. K. Richardson,&nbsp;Jessica L. Rosenberg,&nbsp;Richard S. Ross,&nbsp;Minjung Ryu,&nbsp;Raymond E. Samuel,&nbsp;Nicole Schrode,&nbsp;Susan Schwamberger,&nbsp;Thomas A. Searles,&nbsp;Chandralekha Singh,&nbsp;Alexandra Tingle,&nbsp;Benjamin M. Zwickl","doi":"10.1140/epjqt/s40507-025-00343-4","DOIUrl":"10.1140/epjqt/s40507-025-00343-4","url":null,"abstract":"<div><p>In response to numerous programs seeking to advance quantum education and workforce development in the United States, experts from academia, industry, government, and professional societies convened for a National Science Foundation-sponsored workshop in February 2024 to explore the benefits and challenges of establishing a national center for quantum education. Broadly, such a center would foster collaboration and build the infrastructure required to develop a diverse and quantum-ready workforce. The workshop discussions focused on how a center could uniquely address gaps in public, K-12, and undergraduate quantum information science and engineering (QISE) education. Specifically, the community identified activities that, through a center, could lead to an increase in student awareness of quantum careers, boost the number of educators trained in quantum-related subjects, strengthen pathways into quantum careers, enhance the understanding of the US quantum workforce, and elevate public engagement with QISE. Core proposed activities for the center include professional development for educators, coordinated curriculum development and curation, expanded access to educational laboratory equipment, robust evaluation and assessment practices, network building, and enhanced public engagement with quantum science.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00343-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Search for fast-oscillating fundamental constants with space missions","authors":"Dmitry Budker,&nbsp;Joshua Eby,&nbsp;Marianna S. Safronova,&nbsp;Oleg Tretiak","doi":"10.1140/epjqt/s40507-025-00339-0","DOIUrl":"10.1140/epjqt/s40507-025-00339-0","url":null,"abstract":"<div><p>While it is possible to estimate the dark matter density at the Sun distance from the galactic center, this does not give information on actual dark matter density in the Solar system. There can be considerable local enhancement of dark matter density in the vicinity of gravitating centers, including the Sun, the Earth, as well as other planets in the solar system. Generic mechanisms for the formation of such halos were recently elucidated. In this work, we studies the possible halo dark matter overdensities and corresponding dark matter masses allowed for various objects in the solar system. We explore spacecraft missions to detect such halos with instruments such as quantum clocks, atomic and molecular spectrometers designed to search for fast (tens of hertz to gigahertz) oscillations of fundamental constants, highly sensitive comagnetometers, and other quantum sensors and sensor networks.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00339-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The discriminative ability on anomaly detection using quantum kernels for shipping inspection","authors":"Takao Tomono,&nbsp;Kazuya Tsujimura","doi":"10.1140/epjqt/s40507-025-00335-4","DOIUrl":"10.1140/epjqt/s40507-025-00335-4","url":null,"abstract":"<div><p>We aim to use quantum machine learning to detect various anomalies in image inspection by using small size data. Assuming the possibility that the expressive power of the quantum kernel space is superior to that of the classical kernel space, we are studying a quantum machine learning model. Through trials of image inspection processes not only for factory products but also for products including agricultural products, the importance of trials on real data is recognized. In this study, training was carried out on SVMs embedded with various quantum kernels on a small number of agricultural product image data sets collected in the markets. The quantum kernels prepared in this study consisted of a smaller number of rotating gates and control gates. The F1 scores for each quantum kernel showed a significant effect of using CNOT gates. After confirming the results with a quantum simulator, the usefulness of the quantum kernels was confirmed on a quantum computer. Learning with SVMs embedded with specific quantum kernels showed significantly higher values of the AUC compared to classical kernels. The reason for the lack of learning in quantum kernels is considered to be due to kernel concentration or exponential concentration similar to the Baren plateau. The reason why the F1 score does not increase as the number of features increases is suggested to be due to exponential concentration, while at the same time it is possible that only certain features have discriminative ability. Furthermore, it is suggested that controlled Toffoli gate may be a promising quantum kernel component.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00335-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143668262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterising higher-order phase correlations in gain-switched laser sources with application to quantum key distribution","authors":"Alessandro Marcomini,&nbsp;Guillermo Currás-Lorenzo,&nbsp;Davide Rusca,&nbsp;Angel Valle,&nbsp;Kiyoshi Tamaki,&nbsp;Marcos Curty","doi":"10.1140/epjqt/s40507-025-00340-7","DOIUrl":"10.1140/epjqt/s40507-025-00340-7","url":null,"abstract":"<div><p>Multi-photon emissions in laser sources represent a serious threat for the security of quantum key distribution (QKD). While the decoy-state technique allows to solve this problem, it requires uniform phase randomisation of the emitted pulses. However, gain-switched lasers operating at high repetition rates do not fully satisfy this requirement, as residual photons in the laser cavity introduce correlations between the phases of consecutive pulses. Here, we introduce experimental schemes to characterise the phase probability distribution of the emitted pulses, and demonstrate that an optimisation task over interferometric measures suffices in determining the impact of arbitrary order correlations, which ultimately establishes the security level of the implementation according to recent security proofs. We expect that our findings may find usages beyond QKD as well.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00340-7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel gas sensing principle based on quantum fluctuations","authors":"Eivind Kristen Osestad,&nbsp;Pekka Parviainen,&nbsp;Johannes Fiedler","doi":"10.1140/epjqt/s40507-025-00341-6","DOIUrl":"10.1140/epjqt/s40507-025-00341-6","url":null,"abstract":"<div><p>We present a model of a novel measurement scheme to detect small amounts of a gas species via the ground-state fluctuations of the electromagnetic field (dispersion forces) depending on the entire spectral properties of all objects.</p><p>Here, we describe an a theoretical measurement scheme of optically trapped nanoparticles in a hollow-core fibre. We calculate the effects of the gases on the thermal motion of the nanoparticles and present a neural network-based method for reconstructing the gas concentrations. We present an example of one possible setup capable of detecting concentrations of CO₂ down to 0.01 volume per cent with an accuracy of 1 ppm.</p><p>Reliable detection of small concentrations of specific molecules in a gas is essential for numerous applications such as security and environmental monitoring, medical tests, and production processes. Unlike other measurement schemes, such as surface plasmons or functionalised surfaces, this could allow fast, continuous monitoring and using small sample quantities, without influencing the probe or the sensor system.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00341-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum gravity gradiometry for future mass change science","authors":"Ben Stray,&nbsp;Xavier Bosch-Lluis,&nbsp;Robert Thompson,&nbsp;Clayton Okino,&nbsp;Nan Yu,&nbsp;Norman Lay,&nbsp;Brian Muirhead,&nbsp;Jason Hyon,&nbsp;Holly Leopardi,&nbsp;Peter Brereton,&nbsp;Anand Mylapore,&nbsp;Bryant Loomis,&nbsp;Scott Luthcke,&nbsp;Parminder Ghuman,&nbsp;Srinivas Bettadpur,&nbsp;Maike Diana Lachmann,&nbsp;Thomas Stolz,&nbsp;Christopher Kuehl,&nbsp;Dennis Weise,&nbsp;Holger Ahlers,&nbsp;Christian Schubert,&nbsp;Ahmad Bawamia,&nbsp;Sheng-wey Chiow","doi":"10.1140/epjqt/s40507-025-00338-1","DOIUrl":"10.1140/epjqt/s40507-025-00338-1","url":null,"abstract":"<div><p>A quantum gravity gradiometer in a low Earth orbit, operating in a cross-track configuration, could be a viable single-spacecraft measurement instrument to provide mass change data for Earth observation, at comparable or better resolutions to existing maps generated by GRACE-FO. To reach the sensitivity for these science-grade measurements, many parts of the cold-atom interferometer need to be operating at, or beyond, state-of-the-art performance. In order to raise the maturity of the technology of the cold-atom gradiometer and determine the feasibility of a science-grade instrument, a pathfinder technology demonstration platform is funded. The requirements and a notional design for such a pathfinder and the outstanding challenges for science-grade instruments are presented.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00338-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatially resolved phase reconstruction for atom interferometry","authors":"Stefan Seckmeyer,&nbsp;Holger Ahlers,&nbsp;Jan-Niclas Kirsten-Siemß,&nbsp;Matthias Gersemann,&nbsp;Ernst M. Rasel,&nbsp;Sven Abend,&nbsp;Naceur Gaaloul","doi":"10.1140/epjqt/s40507-025-00337-2","DOIUrl":"10.1140/epjqt/s40507-025-00337-2","url":null,"abstract":"<div><p>Atom interferometers are employed for numerous purposes such as inertial sensing. They measure forces by encoding their signal in phase shifts between matter waves. Signal extraction algorithms typically require the resulting interference patterns to feature a priori known spatial distributions of intensity and phase. Deviations from these assumed spatial distributions, such as those caused by inhomogeneous laser wave fronts, can lead to systematic errors. For long interrogation times, such as for space operation, these distributions can display highly complex structures. We present an extraction algorithm designed for interference patterns featuring arbitrary and unknown temporally stable spatial phase profiles utilizing Principal Component Analysis. It characterizes complex phase profiles and thereby turns effects into a measured quantity which caused systematic errors in previous algorithms. We verify the algorithm’s accuracy and assess the statistical reconstruction error in the presence of atom projection noise as a function of the number of atoms and images. Finally, we extract the spatial phase profiles from experimental data obtained by an atom gravimeter.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00337-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143602098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"LLM-generated tips rival expert-created tips in helping students answer quantum-computing questions","authors":"Lars Krupp,&nbsp;Jonas Bley,&nbsp;Isacco Gobbi,&nbsp;Alexander Geng,&nbsp;Sabine Müller,&nbsp;Sungho Suh,&nbsp;Ali Moghiseh,&nbsp;Arcesio Castaneda Medina,&nbsp;Valeria Bartsch,&nbsp;Artur Widera,&nbsp;Herwig Ott,&nbsp;Paul Lukowicz,&nbsp;Jakob Karolus,&nbsp;Maximilian Kiefer-Emmanouilidis","doi":"10.1140/epjqt/s40507-025-00334-5","DOIUrl":"10.1140/epjqt/s40507-025-00334-5","url":null,"abstract":"<div><p>Alleviating high workloads for teachers is crucial for continuous high quality education. To evaluate if Large Language Models (LLMs) can alleviate this problem in the quantum computing domain, we conducted two complementary studies exploring the use of GPT-4 to automatically generate tips for students. (1) A between-subject survey in which students (N = 46) solved four multiple-choice quantum computing questions with either the help of expert-created or LLMgenerated tips. To correct for possible biases, we additionally introduced two deception conditions. (2) Experienced educators and students (N = 23) directly compared the LLM-generated and expert-created tips. Our results show that the LLM-generated tips were significantly more helpful and pointed better towards relevant concepts while also giving away more of the answers. Furthermore, we found that participants in the first study performed significantly better in answering the quantum computing questions when given tips labeled as LLM-generated, even if they were expert-created. This points towards a placebo effect induced by the participants’ biases for LLM-generated content. Ultimately, we contribute that LLM-generated tips can be used instead of expert tips to support teaching of quantum computing basics.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00334-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143553708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"QSegRNN: quantum segment recurrent neural network for time series forecasting","authors":"Kyeong-Hwan Moon,&nbsp;Seon-Geun Jeong,&nbsp;Won-Joo Hwang","doi":"10.1140/epjqt/s40507-025-00333-6","DOIUrl":"10.1140/epjqt/s40507-025-00333-6","url":null,"abstract":"<div><p>Recently many data centers have been constructed for artificial intelligence (AI) research. The important condition of the data center is to supply sufficient electricity, resulting in many electricity transformers being installed. Especially, these electricity transformers have led to significant heat generation in many data centers. Therefore, managing the temperature of electricity transformers has emerged as an important task. Notably, numerous studies are being conducted to manage and forecast the temperature of electricity transformers using artificial intelligence models. However, as the size of predictive models increases and computational demands grow, substantial computing resources are required. Consequently, there are instances where the lack of computing resources makes these models difficult to operate. To address these challenges, we propose a quantum segment recurrent neural network (QSegRNN), a time series forecasting model utilizing quantum computing. QSegRNN leverages quantum computing to achieve comparable performance with fewer parameters than classical counterpart models under similar conditions. QSegRNN inspired by a classical SegRNN uses the quantum cell instead of the classical cell in the model. The advantage of this structure is that it can be designed with fewer parameters under similar architecture. To construct the quantum cell, we benchmark the quantum convolutional circuit with amplitude embedding as the variational quantum circuit, minimizing information loss while considering the limit of noisy intermediate-scale quantum (NISQ) devices. The experiment result illustrates that the forecasting performance of QSegRNN achieves better performance than SegRNN and other forecasting models even though QSegRNN has only 85 percent of the parameters.</p></div>","PeriodicalId":547,"journal":{"name":"EPJ Quantum Technology","volume":"12 1","pages":""},"PeriodicalIF":5.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://epjquantumtechnology.springeropen.com/counter/pdf/10.1140/epjqt/s40507-025-00333-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143533035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}