Frontiers in Quantum Science and Technology最新文献

{"title":"GINGERINO: a high sensitivity ring laser gyroscope for fundamental and quantum physics investigation","authors":"Francesco Giovinetti, C. Altucci, F. Bajardi, Andrea Basti, N. Beverini, Salvatore Capozziello, G. Carelli, Simone Castellano, D. Ciampini, G. Di Somma, A. D. Di Virgilio, F. Fuso, Gaetano Lambiase, E. Maccioni, Paolo Marsili, A. Ortolan, A. Porzio, R. Velotta","doi":"10.3389/frqst.2024.1363409","DOIUrl":"https://doi.org/10.3389/frqst.2024.1363409","url":null,"abstract":"Ring Laser Gyroscopes, based on the Sagnac effect, are currently the most sensitive rotation sensors. GINGERINO, a RLG installed underground, shows a proved sensitivity that enters the few frad/s regime in about 2.5 days of integration time. On one hand, this sensitivity is well below the shot–noise–level as predicted applying to GINGERINO the so called independent beam model. On the other hand, it paves the way to the use of RLG in fundamental and quantum physics research. Indeed, high sensitivity rotation measurement opens to test general relativity and alternative theory of gravity. Moreover, it make possible to study the interplay between quantum effects in the optical domain and non-inertial reference frames.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"289 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140421590","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Indirect interaction of 13C nuclear spins in diamond with NV centers: simulation of the full J-coupling tensors","authors":"Alexander Nizovtsev, A. Pushkarchuk, Semen Kuten, D. Michels, D. Lyakhov, Nikolai Kargin, S. Kilin","doi":"10.3389/frqst.2024.1332264","DOIUrl":"https://doi.org/10.3389/frqst.2024.1332264","url":null,"abstract":"Recent experiments on the detection, imaging, characterization and control of multiple 13C nuclear spins, as well as of individual 13C–13C dimers in diamond using a single nitrogen-vacancy (NV) center as a sensor, along with the impressive progress in increasing the spectral resolution of such sensor (up to sub-Hertz), have created a request for detailed knowledge of all possible spin interactions in the studied systems. Here, we focus on the indirect interaction (J-coupling) of 13C nuclear spins in diamond, which was not previously taken into account in studies of NV centers. Using two different levels of the density functional theory (DFT), we simulated the full tensors nJKL (K, L = X, Y,Z), describing n-bond J-coupling of nuclear spins 13C in H-terminated diamond-like clusters C10H16 (adamantane) and C35H36, as well as in the cluster C33[NV−]H36 hosting the negatively charged NV− center. We found that, in addition to the usually considered isotropic scalar nJ-coupling constant, the anisotropic contributions to the nJ-coupling tensor are essential. We also showed that the presence of the NV center affects the J-coupling characteristics, especially in the case of 13C–13C pairs located near the vacancy of the NV center.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139847365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Indirect interaction of 13C nuclear spins in diamond with NV centers: simulation of the full J-coupling tensors","authors":"Alexander Nizovtsev, A. Pushkarchuk, Semen Kuten, D. Michels, D. Lyakhov, Nikolai Kargin, S. Kilin","doi":"10.3389/frqst.2024.1332264","DOIUrl":"https://doi.org/10.3389/frqst.2024.1332264","url":null,"abstract":"Recent experiments on the detection, imaging, characterization and control of multiple 13C nuclear spins, as well as of individual 13C–13C dimers in diamond using a single nitrogen-vacancy (NV) center as a sensor, along with the impressive progress in increasing the spectral resolution of such sensor (up to sub-Hertz), have created a request for detailed knowledge of all possible spin interactions in the studied systems. Here, we focus on the indirect interaction (J-coupling) of 13C nuclear spins in diamond, which was not previously taken into account in studies of NV centers. Using two different levels of the density functional theory (DFT), we simulated the full tensors nJKL (K, L = X, Y,Z), describing n-bond J-coupling of nuclear spins 13C in H-terminated diamond-like clusters C10H16 (adamantane) and C35H36, as well as in the cluster C33[NV−]H36 hosting the negatively charged NV− center. We found that, in addition to the usually considered isotropic scalar nJ-coupling constant, the anisotropic contributions to the nJ-coupling tensor are essential. We also showed that the presence of the NV center affects the J-coupling characteristics, especially in the case of 13C–13C pairs located near the vacancy of the NV center.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":" 16","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139787621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Empowering complex-valued data classification with the variational quantum classifier","authors":"Jianing Chen, Yan Li","doi":"10.3389/frqst.2024.1282730","DOIUrl":"https://doi.org/10.3389/frqst.2024.1282730","url":null,"abstract":"The evolution of quantum computers has encouraged research into how to handle tasks with significant computation demands in the past few years. Due to the unique advantages of quantum parallelism and entanglement, various types of quantum machine learning (QML) methods, especially variational quantum classifiers (VQCs), have attracted the attention of many researchers and have been developed and evaluated in numerous scenarios. Nevertheless, most of the research on VQCs is still in its early stages. For instance, as a consequence of the mathematical constraints imposed by the properties of quantum states, the majority of research has not fully taken into account the impact of data formats on the performance of VQCs. In this paper, considering a significant number of data in the real world exist in the form of complex numbers, i.e., phasor data in power systems and the result of Fourier transform on image processing, we develop two categories of data encoding methods, including coupling data encoding and splitting data encoding. This paper features the coupling data encoding method to encode complex-valued data in a way of amplitude encoding. By leveraging the property of quantum states living in a complex Hilbert space, the complex-valued data is embedded into the amplitude of quantum states to comprehensively characterize complex-valued information. Optimizers will be utilized to iteratively tune a parameterized ansatz, with the aim of minimizing the value of loss functions defined with respect to the specific classification task. In addition, distinct factors in VQCs have been explored in detail to investigate the performance of VQCs, including data encoding methods, loss functions, and optimizers. The experimental result shows that the proposed data encoding method outperforms other typical encoding methods on a given classification task. Moreover, different loss functions are tested, and the capability of finding the minimum value is evaluated for gradient-free and gradient-based optimizers, which provides valuable insights and guidelines for practical implementations.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"4 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139796260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Empowering complex-valued data classification with the variational quantum classifier","authors":"Jianing Chen, Yan Li","doi":"10.3389/frqst.2024.1282730","DOIUrl":"https://doi.org/10.3389/frqst.2024.1282730","url":null,"abstract":"The evolution of quantum computers has encouraged research into how to handle tasks with significant computation demands in the past few years. Due to the unique advantages of quantum parallelism and entanglement, various types of quantum machine learning (QML) methods, especially variational quantum classifiers (VQCs), have attracted the attention of many researchers and have been developed and evaluated in numerous scenarios. Nevertheless, most of the research on VQCs is still in its early stages. For instance, as a consequence of the mathematical constraints imposed by the properties of quantum states, the majority of research has not fully taken into account the impact of data formats on the performance of VQCs. In this paper, considering a significant number of data in the real world exist in the form of complex numbers, i.e., phasor data in power systems and the result of Fourier transform on image processing, we develop two categories of data encoding methods, including coupling data encoding and splitting data encoding. This paper features the coupling data encoding method to encode complex-valued data in a way of amplitude encoding. By leveraging the property of quantum states living in a complex Hilbert space, the complex-valued data is embedded into the amplitude of quantum states to comprehensively characterize complex-valued information. Optimizers will be utilized to iteratively tune a parameterized ansatz, with the aim of minimizing the value of loss functions defined with respect to the specific classification task. In addition, distinct factors in VQCs have been explored in detail to investigate the performance of VQCs, including data encoding methods, loss functions, and optimizers. The experimental result shows that the proposed data encoding method outperforms other typical encoding methods on a given classification task. Moreover, different loss functions are tested, and the capability of finding the minimum value is evaluated for gradient-free and gradient-based optimizers, which provides valuable insights and guidelines for practical implementations.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"4 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139856202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dark resonance spectra of trapped ions under the influence of micromotion","authors":"Nicol'as Adri'an Nunez Barreto, Muriel Bonetto, M. Luda, Cecilia Cormick, C. Schmiegelow","doi":"10.3389/frqst.2024.1381117","DOIUrl":"https://doi.org/10.3389/frqst.2024.1381117","url":null,"abstract":"We study the influence of micromotion on the spectrum of trapped ions with a lambda-type level scheme, leading to dark resonances due to coherent population trapping. We work with calcium ions trapped in a ring-shaped Paul trap, in which one can compensate excess micromotion for only one ion of the crystal. We observe that micromotion affects the shapes of the dark resonances and causes the appearance of “echoes” separated by intervals given by the drive frequency. We present a theoretical model that provides good fits to the measurements and can be used to estimate the amplitude of the micromotion modulation of the atomic motion. We estimate an effective temperature of the ions from the spectra and observe clear micromotion heating as well as impaired cooling for sufficiently large excess micromotion.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"86 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140462495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning meets quantum mechanics in catalysis","authors":"J. P. Lewis, Pengju Ren, Xiaodong Wen, Yongwang Li, Guanhua Chen","doi":"10.3389/frqst.2023.1232903","DOIUrl":"https://doi.org/10.3389/frqst.2023.1232903","url":null,"abstract":"Over the past decade many researchers have applied machine learning algorithms with computational chemistry and materials science tools to explore properties of catalysts. There is a rapid increase in publications demonstrating the use of machine learning for rational catalyst design. In our perspective, targeted tools for rational catalyst design will continue to make significant contributions. However, the community should focus on developing high-throughput simulation tools that utilize molecular dynamics capabilities for thorough exploration of the complex potential energy surfaces that exist, particularly in heterogeneous catalysis. Catalyst-specific databases should be developed to contain enough data to represent the complex multi-dimensional space that defines structure-function relationships. Machine learning tools will continue to impact rational catalyst design; however, we believe that more sophisticated pattern recognition algorithms would yield better understanding of structure-function relationships for heterogeneous catalysis.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129171019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Robust atomic states for quantum information with continuous variables","authors":"A. Vudayagiri, Bappaditya Sankhari","doi":"10.3389/frqst.2023.1139597","DOIUrl":"https://doi.org/10.3389/frqst.2023.1139597","url":null,"abstract":"Using a set of Zeeman sublevels of an alkali atom such as rubidium or sodium, we propose to construct a pair of coherentc population trap (CPT) states, which can be individually addressed and populated at will. The system can be arranged such that there exists a dressed state that is a linear combination of these two CPT states. We have earlier shown the capability of forming discrete quantum gates using this configuration [J.Phys. B, (2006), 39, 3919]. In the present communication, we will show how the same configuration can be used to prepare and operate continuously varying states. The state can be mapped to a 2D parametric space in such a way that any desired vector within it can be prepared, and a continuous, adiabatic evolution from one vector to another is also possible. A method to exploit a continuous interaction potential, which can be used in quantum computation, is also suggested. We discuss how a continuous variable quantum computation can be performed using such states.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124418576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multimodal quantum metrology in living systems using nitrogen-vacancy centres in diamond nanocrystals","authors":"J. Hart, H. Knowles","doi":"10.3389/frqst.2023.1220015","DOIUrl":"https://doi.org/10.3389/frqst.2023.1220015","url":null,"abstract":"Nitrogen-vacancy centres in diamond nanocrystals are among the leading candidates for realising nanoscale quantum sensing under ambient conditions. Due to their exceptional electronic spin coherence at room temperature and optical addressability, these solid state spin-based sensors can achieve a wide selection of sensing modalities, including probing temperature, external magnetic and electric field, as well as the detection of nearby electronic and nuclear spins. In this article, we discuss recent progress made utilizing nanodiamond quantum sensors in living systems and explore both opportunities for future advances and challenges that lie ahead.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126316101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards a quantum ready workforce: the updated European Competence Framework for Quantum Technologies","authors":"Franziska Greinert, Rainer Müller, Simon Goorney, Jacob Sherson, M. Ubben","doi":"10.3389/frqst.2023.1225733","DOIUrl":"https://doi.org/10.3389/frqst.2023.1225733","url":null,"abstract":"The European Competence Framework for Quantum Technologies is rapidly evolving into the basic common language for educational efforts, comparison of training offerings, mapping of courses and development of educational modules. It has been compiled within the European Quantum Flagship coordination and support projects QTEdu and QUCATS. It is central, e.g., in the European Quantum Readiness Center and will be the starting point for a European certification scheme to standardise industry training. For version 2.0, released in April 2023, the framework has been updated and extended, e.g., with descriptions of the proficiency levels A1 to C2. The framework is structured into eight domains with 42 subdomains, each covering several topics and subtopics. This report briefly documents the update process and the role of the framework in quantum technology education.","PeriodicalId":108649,"journal":{"name":"Frontiers in Quantum Science and Technology","volume":"210 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115769028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}