Materials for Quantum Technology最新文献

{"title":"Spectroscopy and coherent control of two-level system defect ensembles using a broadband 3D waveguide","authors":"Qianxu Wang, Juan Sebastian Salcedo-Gallo, Salil Bedkihal, Tian Xia, Maciej Olszewski, Valla Fatemi, Mattias Fitzpatrick","doi":"10.1088/2633-4356/ae2b43","DOIUrl":"https://doi.org/10.1088/2633-4356/ae2b43","url":null,"abstract":"Abstract Defects in solid-state materials play a central role in determining coherence, stability, and performance in quantum technologies. Although narrowband techniques can probe specific resonances with high precision, a broadband spectroscopic approach captures the full spectrum of defect properties and dynamics. Two-level system (TLS) defects in amorphous dielectrics are a particularly important example because they are major sources of decoherence and energy loss in superconducting quantum devices. However, accessing and characterizing their collective dynamics remains far more challenging than probing individual TLS defects. Building on our previously developed Broadband Cryogenic Transient Dielectric Spectroscopy (BCTDS) technique, we study the coherent control and time-resolved dynamics of TLS defect ensembles over a wide frequency range of 3–5 GHz without requiring full device fabrication. Unlike conventional approaches limited to narrow spectral windows and fully fabricated devices, BCTDS enables modular, device-independent measurements that reveal quantum interference effects, memory-dependent dynamics, and dressed-state evolution within the TLS defect bath. The spectral response reveals distinct V-shaped structures corresponding to the bare eigenmode frequencies. Using these features, we extract a TLS defect spectral density of 84 GHz −1 for a silicon sample, across a 4.1–4.6 GHz span. Furthermore, we systematically investigate amplitude- and phase-controlled interference fringes for multiple temperatures and inter-pulse delays, providing direct evidence of coherent dynamics and control. A driven minimal spin model with dipole–dipole interactions that qualitatively capture the observed behavior is presented. Our results establish BCTDS as a versatile platform for broadband defect spectroscopy, offering new capabilities for diagnosing and mitigating sources of decoherence, engineering many-body dynamics, and exploring non-equilibrium phenomena in disordered quantum systems.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"5 4","pages":"045201-045201"},"PeriodicalIF":0.0,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147882046","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nitrogen-vacancy centers in diamond: discovery of additional electronic states","authors":"Minh-Tuan Luu, Ali Tayefeh Younesi, Ronald Ulbricht","doi":"10.1088/2633-4356/ad61b3","DOIUrl":"https://doi.org/10.1088/2633-4356/ad61b3","url":null,"abstract":"\u0000 Nitrogen-vacancy (NV) defect centers in diamond are key to applications in quantum sensing and quantum computing. They create localized electronic states in the diamond lattice with distinct population relaxation pathways following photoexcitation that ultimately enable its unique properties. The defect is known to exist in two charge states: neutral and negative, with respectively one and two known optically-active electronic transitions. Here, we report on the observation of a large number of hitherto undiscovered excited electronic states in both charge states as evidenced by distinct optical transitions in the infrared to ultraviolet part of the spectrum. These transitions are observed by monitoring the electronic relaxation of NV centers after photoexcitation using transient absorption spectroscopy, directly probing transient phenomena occurring on timescales from femtoseconds to microseconds. We also for the first time probed the electron transfer dynamics from the 3E state of NV− to nearby single-substitutional nitrogen defects hat leads to the well-known effect of NV photoluminescence quenching.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"10 15","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141661611","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":"Fabrication of tips for scanning probe magnetometry by diamond growth","authors":"Arne Götze, Xavier Vidal, Nicola Lang, Christian Giese, Patricia Quellmalz, Jan Jeske, Peter Knittel","doi":"10.1088/2633-4356/ad589d","DOIUrl":"https://doi.org/10.1088/2633-4356/ad589d","url":null,"abstract":"\u0000 The use of quantum sensors is promising detailed insights into physical phenomena such as magnetism or superconductivity. One example of such quantum sensors is a microscopic diamond tip containing nitrogen vacancy (NV) centers, which is capable of producing correlated measurements of vectorial magnetic fields and the sample topography on the nanoscale. In this study, we present a chemical vapor deposition (CVD) process to produce diamond tips with NV centers by overgrowing microstructured diamond substrates. The resulting diamond tips exhibit a radius of curvature of approximately 10 nm, suitable for use as a probe in an atomic force microscope (AFM). The magnetic sensitivity of the CVD-grown diamond tips is characterized with pulsed measurements of the optically detected magnetic resonance (ODMR), which yield a minimum magnetic sensitivity of 60 µT/√Hz. The growth of the diamond microstructures is observed to differ from the commonly used geometric model predicting CVD growth of bulk diamond crystals. We identify an empirical model for the growth behavior of the microstructures by taking into account processes described in the step flow growth model for crystals. Additionally, we demonstrate the applicability of the developed CVD growth process to membrane substrates required for the preparation of magnetometry-capable diamond tips.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"67 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141337935","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":"GaAs-on-insulator ridge waveguide nanobeam cavities with integrated InAs quantum dots","authors":"Yueguang Zhou, Yuhui Yang, Yujing Wang, A. Koulas‐Simos, C. Palekar, I. Limame, Shulun Li, Hanqing Liu, H. Ni, Zhichuan Niu, Kresten Yvind, N. Gregersen, M. Pu, S. Reitzenstein","doi":"10.1088/2633-4356/ad5823","DOIUrl":"https://doi.org/10.1088/2633-4356/ad5823","url":null,"abstract":"\u0000 This study investigates nanobeam cavities on a GaAs-on-insulator chip with InAs quantum dots, including design, fabrication, and experimental characterization. The nanobeam cavities are optimized for high photon coupling efficiency and pronounced light-matter coupling. Numerical studies yield Q factors up to about 1400, a coupling efficiency of nearly 70% and a maximum Purcell factor of approximately 100. Experimentally, these devices have a $Q$ factor of about 1300, and comparing the lifetime of quantum dots in on-resonance and off-resonance conditions, a Purcell factor of 10.46±0.14 is obtained. Moreover, in the single-emitter regime, we observe strong multiphoton suppression with g(2)(0) = 0.295. Our results demonstrate the high potential of nanobeam cavity on a GaAs-on-insulator platform for quantum photonic applications.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"26 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141346122","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":"Quantum materials engineering by structured cavity vacuum fluctuations","authors":"Hannes Huebener, Emil Viñas~Boström, Martin Claassen, S. Latini, Angel Rubio","doi":"10.1088/2633-4356/ad4e8b","DOIUrl":"https://doi.org/10.1088/2633-4356/ad4e8b","url":null,"abstract":"\u0000 A paradigm shift in the research of optical cavities is taking place, focusing on the properties of materials inside cavities. The possibility to affect changes of material groundstates with or without actual photon population inside cavities is an avenue that promises a novel view of materials science and provides a new knob to control quantum phenomena in materials. Here, we present three theoretical scenarios where such groundstate quantum phase transition is predicted by the coupling of the matter to mere vacuum fluctuations of the cavity, as a realizations of cavity materials engineering in the dark.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"20 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141117380","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":"Structural formation yield of GeV centers from implanted Ge in diamond","authors":"Ulrich Wahl, J G Correia, Ângelo Rafael Granadeiro Costa, Afonso Lamelas, Vitor S Amaral, Karl Johnston, G. Magchiels, S. M. Tunhuma, A. Vantomme, L.M.C. Pereira","doi":"10.1088/2633-4356/ad4b8d","DOIUrl":"https://doi.org/10.1088/2633-4356/ad4b8d","url":null,"abstract":"\u0000 In order to study the structural formation yield of germanium-vacancy (GeV) centers from implanted Ge in diamond, we have investigated its lattice location by using the β− emission channeling technique from the radioactive isotope 75Ge (t\u0000 1/2=83 min) produced at the ISOLDE/CERN facility. 75Ge was introduced via recoil implantation following 30 keV ion implantation of the precursor isotope 75Ga (126 s) with fluences around 2×1012 - 5×1013 cm−2. While for room temperature implantation fractions around 20% were observed in split-vacancy configuration and 45% substitutional Ge, following implantation or annealing up to 900°C, the split-vacancy fraction dropped to 6-9% and the substitutional fraction reached 85-96%. GeV complexes thus show a lower structural formation yield than other impurities, with substitutional Ge being the dominant configuration. Moreover, annealing or high-temperature implantation seem to favour the formation of substitutional Ge over GeV. Our results strongly suggest that GeV complexes are thermally unstable, and transformed to substitutional Ge by capture of mobile carbon interstitials, which is likely to contribute to the difficulties in achieving high formation yields of these optically active centers.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"30 50","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140980450","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":"Low-loss α-tantalum coplanar waveguide resonators on silicon wafers: fabrication, characterization and surface modification","authors":"D. Lozano, M. Mongillo, Xiaoyu Piao, S. Couet, Danny Wan, Y. Canvel, A. M. Vadiraj, T. Ivanov, J. Verjauw, R. Acharya, J. Van Damme, Mohiyaddin A. Fahd, J. Jussot, P. P. Gowda, Antoine Pacco, B. Raes, J. van de Vondel, Iuliana Radu, Bogdan Govoreanu, J. Swerts, Anton Potocnik, Kristiaan DeGreve","doi":"10.1088/2633-4356/ad4b8c","DOIUrl":"https://doi.org/10.1088/2633-4356/ad4b8c","url":null,"abstract":"\u0000 The performance of state-of-the-art superconducting quantum devices is currently limited by microwave dielectric loss at different interfaces. α-tantalum is a superconductor that has proven effective in reducing dielectric loss and improving device performance due to its thin low-loss oxide. Here, we demonstrate the fabrication of high-quality factor α-tantalum coplanar-waveguide resonators directly on pristine 300 mm silicon wafers over a variety of metal deposition conditions and perform a comprehensive material and electrical characterization study. Additionally, we apply a surface treatment based on hydrofluoric acid that allows us to modify different resonators surfaces, leading to a reduction in two-level system (TLS) loss in the devices by a factor of three. This loss reduction can be entirely attributed to the removal of surface oxides. Our study indicates that large scale manufacturing of low-loss superconducting circuits should indeed be feasible and suggests a viable avenue to materials-driven advancements in superconducting circuit performance.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"12 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140981736","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":"Efficient characterization of blinking quantum emitters from scarce data sets via machine learning","authors":"G. Landry, Carlo Bradac","doi":"10.1088/2633-4356/ad2e3b","DOIUrl":"https://doi.org/10.1088/2633-4356/ad2e3b","url":null,"abstract":"Abstract Single photon emitters are core building blocks of quantum technologies, with established and emerging applications ranging from quantum computing and communication to metrology and sensing. Regardless of their nature, quantum emitters universally display fluorescence intermittency or photoblinking: interaction with the environment can cause the emitters to undergo quantum jumps between on and off states that correlate with higher and lower photoemission events, respectively. Understanding and quantifying the mechanism and dynamics of photoblinking is important for both fundamental and practical reasons. However, the analysis of blinking time traces is often afflicted by data scarcity. Blinking emitters can photo-bleach and cease to fluoresce over time scales that are too short for their photodynamics to be captured by traditional statistical methods. Here, we demonstrate two approaches based on machine learning that directly address this problem. We present a multi-feature regression algorithm and a genetic algorithm that allow for the extraction of blinking on/off switching rates with ⩾85% accuracy, and with ⩾10× less data and ⩾20× higher precision than traditional methods based on statistical inference. Our algorithms effectively extend the range of surveyable blinking systems and trapping dynamics to those that would otherwise be considered too short-lived to be investigated. They are therefore a powerful tool to help gain a better understanding of the physical mechanism of photoblinking, with practical benefits for applications based on quantum emitters that rely on either mitigating or harnessing the phenomenon.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"4 1","pages":"015403-015403"},"PeriodicalIF":0.0,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://iopscience.iop.org/article/10.1088/2633-4356/ad2e3b/pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147904822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent progress in undoped group-IV heterostructures for quantum technologies","authors":"C. Tai, Jiun-Yun Li","doi":"10.1088/2633-4356/ad2980","DOIUrl":"https://doi.org/10.1088/2633-4356/ad2980","url":null,"abstract":"\u0000 Silicon has been a core material for digital computing owing to its high mobility, stability oxide interface, mature manufacturing technologies for more than half a century. While Moore’s law seems to further advance via various technologies to extend its expiration date, some intractable problems that requires processing times growing exponentially cannot be solved in a reasonable scale of time. Meanwhile, quantum computing is a promising tool to perform calculations much more efficiently than classical computing for certain types of problems. To realize a practical quantum computer, quantum dots on group-IV semiconductor heterostructures are promising due to the long decoherence time, scalability, and compatibility with the Si VLSI technology. In this review, we start with the advancement of group-IV undoped heterostructures since 2000 and review carrier transport properties in these undoped heterostructure. We also review the hole effective masses, spin-orbit coupling, and effective g-factors in the Ge-based heterostructures and conclude with a brief summary.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"55 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139777902","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":"Recent progress in undoped group-IV heterostructures for quantum technologies","authors":"C. Tai, Jiun-Yun Li","doi":"10.1088/2633-4356/ad2980","DOIUrl":"https://doi.org/10.1088/2633-4356/ad2980","url":null,"abstract":"\u0000 Silicon has been a core material for digital computing owing to its high mobility, stability oxide interface, mature manufacturing technologies for more than half a century. While Moore’s law seems to further advance via various technologies to extend its expiration date, some intractable problems that requires processing times growing exponentially cannot be solved in a reasonable scale of time. Meanwhile, quantum computing is a promising tool to perform calculations much more efficiently than classical computing for certain types of problems. To realize a practical quantum computer, quantum dots on group-IV semiconductor heterostructures are promising due to the long decoherence time, scalability, and compatibility with the Si VLSI technology. In this review, we start with the advancement of group-IV undoped heterostructures since 2000 and review carrier transport properties in these undoped heterostructure. We also review the hole effective masses, spin-orbit coupling, and effective g-factors in the Ge-based heterostructures and conclude with a brief summary.","PeriodicalId":345750,"journal":{"name":"Materials for Quantum Technology","volume":"51 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139837452","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}