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Pulse design of baseband flux control for adiabatic controlled-phase gates in superconducting circuits

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Physical Review Applied 2025年第6期23卷 064013-064013页

作者： Qi Ding Alan V. Oppenheim Petros T. Boufounos Simon Gustavsson Jeffrey A. Grover Thomas A. Baran William D. Oliver Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA Mitsubishi Electric Research Laboratories Cambridge Massachusetts 02139 USA Present address: Atlantic Quantum Cambridge Massachusetts 02139 USA. Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA

Despite progress towards achieving low error rates with superconducting qubits, error-prone two-qubit gates remain a bottleneck for realizing large-scale quantum computers. Therefore, a systematic framework to design high-fidelity gates becomes imperative. One type of two-qubit gate in superconducting qubits is the controlled-phase (cphase) gate, which utilizes a conditional interaction between higher-energy levels of the qubits controlled by a baseband flux pulse on one of the qubits or a tunable coupler. In this work, we study an adiabatic implementation of cphase gates and formulate the design of the control trajectory for the gate as a pulse-design problem. We show in simulation that the Chebyshev-based trajectory can, in certain cases, enable gates with gate infidelity lower by an average of 23.3% when compared to the widely used Slepian-based trajectory.

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A Comprehensive Overview and Survey of O-RAN: Exploring Slicing-aware Architecture, Deployment Options, and Use Cases

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arXiv 2024年

作者： Alam, Khurshid Habibi, Mohammad Asif Tammen, Matthias Krummacker, Dennis Saad, Walid Di Renzo, Marco Melodia, Tommaso Costa-Pérez, Xavier Debbah, Mérouane Dutta, Ashutosh Schotten, Hans D. Kaiserslautern67663 Germany Kaiserslautern67663 Germany The Department of Electrical and Computer Engineering Virginia Tech Virginia22203 United States Université Paris-Saclay CNRS CentraleSupélec Laboratoire des Signaux et Systèmes 3 Rue Joliot-Curie Gif-sur-Yvette91192 France The Institute for the Wireless Internet of Things Northeastern University BostonMA02115 United States The 6G Networks R&D Department NEC Laboratories Europe Heidelberg69115 Germany Barcelona08034 Spain Khalifa University of Science and Technology P. O. Box 127788 Abu Dhabi United Arab Emirates The Applied Physics Laboratory Johns Hopkins University Maryland20723 United States

Open-radio access network (O-RAN) seeks to establish principles of openness, programmability, automation, intelligence, and hardware-software disaggregation with interoperable interfaces. It advocates for multi-vendorism and multistakeholderism within a cloudified and virtualized wireless infrastructure, aimed at enhancing the deployment, operation, and maintenance of RAN architecture. This enhancement promises increased flexibility, performance optimization, service innovation, energy efficiency, and cost efficiency in fifth-generation (5G), sixth-generation (6G), and future networks. One of the key features of the O-RAN architecture is its support for network slicing, which entails interaction with other slicing domains within a mobile network, notably the transport network (TN) domain and the core network (CN) domain, to realize end-to-end (E2E) network slicing. The study of this feature requires exploring the stances and contributions of diverse standards development organizations (SDOs). In this context, we note that despite the ongoing industrial deployments and standardization efforts, the research and standardization communities have yet to comprehensively address network slicing in O-RAN. To address this gap, this survey paper provides a comprehensive exploration of network slicing in O-RAN through an in-depth review of specification documents from O-RAN Alliance and research papers from leading industry and academic institutions. The paper commences with an overview of the ongoing standardization efforts and open-source contributions associated with ORAN, subsequently delving into the latest O-RAN architecture with an emphasis on its slicing aspects. Further, the paper explores deployment scenarios for network slicing within O-RAN, examining options for the deployment and orchestration of ORAN and TN network slice subnets. It discusses the slicing of the underlying infrastructure, encompassing both TNs and compute resource slicing. Finally, the paper provi

关键词： 5G mobile communication systems

Joint channel estimation and data detection in cell-free massive MU-MIMO systems

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arXiv 2021年

作者： Song, Haochuan Goldstein, Tom You, Xiaohu Zhang, Chuan Tirkkonen, Olav Studer, Christoph the LEADS Southeast University Nanjing China the National Mobile Communications Research Laboratory Southeast University Nanjing China the Purple Mountain Laboratories Nanjing China the Department of Computer Science University of Maryland College ParkMD United States the Department of Communications and Networking Aalto University Espoo Finland the Department of Information Technology and Electrical Engineering ETH Zurich Zurich Switzerland

We propose a joint channel estimation and data detection (JED) algorithm for densely-populated cell-free massive multiuser (MU) multiple-input multiple-output (MIMO) systems, which reduces the channel training overhead caused by the presence of hundreds of simultaneously transmitting user equipments (UEs). Our algorithm iteratively solves a relaxed version of a maximum a-posteriori JED problem and simultaneously exploits the sparsity of cell-free massive MU-MIMO channels as well as the boundedness of QAM constellations. In order to improve the performance and convergence of the algorithm, we propose methods that permute the access point and UE indices to form so-called virtual cells, which leads to better initial solutions. We assess the performance of our algorithm in terms of root-mean-squared-symbol error, bit error rate, and mutual information, and we demonstrate that JED significantly reduces the pilot overhead compared to orthogonal training, which enables reliable communication with short packets to a large number of UEs. Copyright © 2021, The Authors. All rights reserved.

关键词： MIMO systems

Correlation Analysis with Experimental Procedures and Peak Structures in Xps Spectral Round-Robin Tests on Mno Powder Sample

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SSRN

SSRN 2022年

作者： Murakami, Ryo Harada, Yoshitomo Sonobayashi, Yutaka Oji, Hiroshi Makino, Hisao Tanaka, Hiromi Taguchi, Hideyuki Sakamoto, Takanori Morita, Haruka Wakamori, Akihiko Kibe, Naoko Nishida, Shinsuke Nagata, Kenji Shinotsuka, Hiroshi Shouno, Hayaru Yoshikawa, Hideki The University of Electro-Communications Graduate School of Informatics and Engineering Chofu182-8585 Japan National Institute for Materials Science Research and Services Division of Materials Data and Integrated System Ibaraki Tsukuba305-0044 Japan Kyoto University Department of Materials Science and Engineering Kyoto606-8501 Japan Nagoya University Synchrotron radiation Research center Nagoya464-8603 Japan Kochi University of Technology School of Systems Engineering Japan National Institute of Technology Yonago College Department of Electrical and Computer Engineering Japan Nihon Parkerizing Co. Ltd Central Research Laboratories Kanagawa 254-0012 Japan JX Nippon Mining & Metals Corporation Technology Development Center Japan Melco Semiconductor Engineering Corporation Chemical Analysis & Evaluation Engineering Dept. Fukuoka Japan Kobelco Welding TechnoSolutions Co. Technical Solution Dept. Ltd Kanagawa 251-8551 Japan Furukawa Electric Co. Ltd Analysis Technology Center Sustainable Technology Laboratorie Kanagawa 220-0073 Japan

Spectral measurements provide valuable information on the electronic states and crystal structures of materials. In particular, X-ray photoelectron spectroscopy (XPS) can facilitate analysis of the chemical bond state of material surfaces. In the analysis of XPS spectra, the spectrum to be measured is typically compared to a reference spectrum measured on a known single-phase sample. Therefore, establishing a reference spectral database is imperative. In this study, round-robin tests of XPS spectra are performed with the aim of obtaining recommended XPS reference spectra and experimental procedures, including preprocessing. Determining the variations in peak structures between instrument- and sample-derived spectral shapes, and quantitatively discussing them in round-robin tests of XPS spectra are challenging. Therefore, an analysis method that automatically determines the above mentioned variations and extracts the samplederived common spectral structures is developed. This study presents a new approach to the quantitative analysis of round-robin tests of XPS spectra. The required common © 2022, The Authors. All rights reserved.

关键词： X ray photoelectron spectroscopy

Roadmap on Nonlocality in Photonic Materials and Metamaterials

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arXiv 2025年

作者： Monticone, Francesco Mortensen, N. Asger Fernández-Domínguez, Antonio I. Luo, Yu Tserkezis, Christos Khurgin, Jacob B. Shahbazyan, Tigran V. Chaves, André J. Peres, Nuno M.R. Wegner, Gino Busch, Kurt Hu, Huatian della Sala, Fabio Zhang, Pu Ciracì, Cristian Aizpurua, Javier Babaze, Antton Borisov, Andrei G. Chen, Xue-Wen Christensen, Thomas Yan, Wei Yang, Yi Hohenester, Ulrich Huber, Lorenz Wubs, Martijn de Liberato, Simone Gonçalves, P.A.D. de Abajo, F. Javier García Hess, Ortwin Tarasenko, Illya Cox, Joel D. Jelver, Line Dias, Eduardo J.C. Sánchez, Miguel Sánchez Margetis, Dionisios Gómez-Santos, Guillermo Stauber, Tobias Tretyakov, Sergei Simovski, Constantin Pakniyat, Samaneh Gómez-Díaz, J. Sebastián Bondarev, Igor V. Biehs, Svend-Age Boltasseva, Alexandra Shalaev, Vladimir M. Krasavin, Alexey V. Zayats, Anatoly V. Alù, Andrea Song, Jung-Hwan Brongersma, Mark L. Levy, Uriel Long, Olivia Y. Guo, Cheng Fan, Shanhui Bozhevolnyi, Sergey I. Overvig, Adam Prudêncio, Filipa R. Silveirinha, Mário G. Gangaraj, S. Ali Hassani Argyropoulos, Christos Huidobro, Paloma A. Galiffi, Emanuele Yang, Fan Pendry, John B. Miller, David A.B. School of Electrical and Computer Engineering Cornell University IthacaNY14853 United States POLIMA Center for Polariton-driven Light–Matter Interactions University of Southern Denmark Campusvej 55 Odense MDK-5230 Denmark D-IAS—Danish Institute for Advanced Study University of Southern Denmark Campusvej 55 Odense MDK-5230 Denmark Departamento de Física Teórica de la Materia Condensada Universidad Autónoma de Madrid MadridE-28049 Spain Universidad Autónoma de Madrid MadridE-28049 Spain School of Electrical and Electronic Engineering Nanyang Technological University Singapore639798 Singapore Key Laboratory of Radar Imaging and Microwave Photonics Ministry of Education College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Nanjing211106 China Department of Electrical and Computer Engineering Johns Hopkins University BaltimoreMD21218 United States Department of Physics Jackson State University JacksonMS39217 United States Department of Physics Aeronautics Institute of Technology SP So Jos dos Campos12228-900 Brazil Departamento de Física Universidade do Minho BragaP-4710-057 Portugal Av Mestre José Veiga Braga4715-330 Portugal Max-Born-Institut Berlin12489 Germany Humboldt-Universität zu Berlin Institut für Physik AG Theoretische Optik and Photonik Berlin12489 Germany Center for Biomolecular Nanotechnologies Istituto Italiano di Tecnologia Via Barsanti 14 Arnesano73010 Italy Via Monteroni Campus Unisalento Lecce73100 Italy School of physics Huazhong University of Science and Technology Luoyu Road 1037 Wuhan430074 China Donostia International Physics Center DIPC Donostia-San Sebastián20018 Spain Ikerbasque Basque Foundation for Science Bilbao48009 Spain Department of Electricity and Electronics University of the Basque Country Leioa48940 Spain Department of Applied Physics University of the Basque Country Donostia20018 Spain Université Paris-Saclay CNRS Institut des Scienc

Photonic technologies continue to drive the quest for new optical materials with unprecedented responses. A major frontier in this field is the exploration of nonlocal (spatially dispersive) materials, going beyond the local, wavevector-independent assumption traditionally made in optical material modeling. On one end, the growing interest in plasmonic, polaritonic and quantum materials has revealed naturally occurring nonlocalities, emphasizing the need for more accurate models to predict and design their optical responses. This has major implications also for topological, nonreciprocal, and time-varying systems based on these material platforms. Beyond natural materials, artificially structured materials—metamaterials and metasurfaces–can provide even stronger and engineered nonlocal effects, emerging from long-range interactions or multipolar effects. This is a rapidly expanding area in the field of photonic metamaterials, with open frontiers yet to be explored. In the case of metasurfaces, in particular, nonlocality engineering has become a powerful tool for designing strongly wavevector-dependent responses, enabling enhanced wavefront control, spatial compression, multifunctional devices, and wave-based computing. Furthermore, nonlocality and related concepts play a critical role in defining the ultimate limits of what is possible in optics, photonics, and wave physics. This Roadmap aims to survey the most exciting developments in nonlocal photonic materials, highlight new opportunities and open challenges, and chart new pathways that will drive this emerging field forward–toward new scientific discoveries and technological advancements. Copyright © 2025, The Authors. All rights reserved.

关键词： Nanocrystals

Quantum repeaters: From quantum networks to the quantum internet

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Reviews of Modern Physics 2023年第4期95卷 045006-045006页

作者： Koji Azuma Sophia E. Economou David Elkouss Paul Hilaire Liang Jiang Hoi-Kwong Lo Ilan Tzitrin NTT Basic Research Laboratories NTT Corporation 3-1 Morinosato-Wakamiya Atsugi Kanagawa 243-0198 Japan and NTT Research Center for Theoretical Quantum Information NTT Corporation 3-1 Morinosato-Wakamiya Atsugi Kanagawa 243-0198 Japan Department of Physics Virginia Tech Blacksburg Virginia 24061 USA QuTech Delft University of Technology Lorentzweg 1 2628 CJ Delft The Netherlands and Networked Quantum Devices Unit Okinawa Institute of Science and Technology Graduate University Okinawa Japan Department of Physics Virginia Tech Blacksburg Virginia 24061 USA and Quandela SAS 10 Boulevard Thomas Gobert 91120 Palaiseau France Pritzker School of Molecular Engineering The University of Chicago Chicago Illinois 60637 USA Quantum Bridge Technologies Inc. 100 College Street Toronto Ontario M5G 1L5 Canada Department of Physics University of Hong Kong Pokfulam Hong Kong and Center for Quantum Information and Quantum Control Department of Physics and Department of Electrical and Computer Engineering University of Toronto Toronto Ontario M5S 3G4 Canada Department of Physics University of Toronto Toronto Ontario Canada

A quantum internet is the holy grail of quantum information processing, enabling the deployment of a broad range of quantum technologies and protocols on a global scale. However, numerous challenges must be addressed before the quantum internet can become a reality. Perhaps the most crucial of these is the realization of a quantum repeater, an essential component in the long-distance transmission of quantum information. As the analog of a classical repeater, extender, or booster, the quantum repeater works to overcome loss and noise in the quantum channels constituting a quantum network. Here the conceptual frameworks and architectures for quantum repeaters, as well as the experimental progress toward their realization, are reviewed. Various near-term proposals to overcome the limits to the communication rates set by point-to-point quantum communication are also discussed. Finally, the manner in which quantum repeaters fit within the broader challenge of designing and implementing a quantum internet is overviewed.

关键词： Quantum communication Quantum memories Quantum networks Quantum repeaters Internet

Current spike suppression techniques for magnetic bearing amplifier 34

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Current spike suppression techniques for magnetic bearing am...

34th Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2019

作者： Hsieh, Hsin-Che Chen, Cheng-Wei Chen, Ming-Cheng Lai, Jih-Sheng Jason Lin, Jin-Mu Bradley Department of Electrical and Computer Engineering Virginia Polytechnic Institute and State University Blacksburg United States Department of Electronic and Computer Engineering National Taiwan University of Science and Technology Taipei Taiwan Green Energy and Environment Research Laboratories Industrial Technology Research Institute Hsinchu Taiwan

ISBN: (纸本)9781538683309

The levitation coils or electromagnets designed for active magnetic bearing application typically have relatively large parasitic capacitance due to their large number of turns. When these coils are driven by a switching amplifier, the parasitic capacitance can cause current spikes and ringing during the switching process. As a magnetic bearing typically consists of multiple sets of coils for axial and radial directional controls, these spikes may interfere with sensors in the magnetic bearing system or cause false trigger of other sets of coils. In this paper, two current spike suppression methods are presented, and the effectiveness of each method is verified through experiments. © 2019 IEEE.

关键词： Capacitance

Antiferroelectric negative capacitance from a structural phase transition in zirconia

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arXiv 2021年

作者： Hoffmann, Michael Wang, Zheng Tasneem, Nujhat Zubair, Ahmad Ravindran, Prasanna Venkat Tian, Mengkun Gaskell, Anthony Triyoso, Dina Consiglio, Steven Tapily, Kanda Clark, Robert Hur, Jae Pentapati, Sai Surya Kiran Dopita, Milan Yu, Shimeng Chern, Winston Kacher, Josh Reyes-Lillo, Sebastian E. Antoniadis, Dimitri Ravichandran, Jayakanth Slesazeck, Stefan Mikolajick, Thomas Khan, Asif Islam NaMLab GGmbH Dresden01187 Germany School of Electrical and Computer Engineering Georgia Institute of Technology AtlantaGA30332 United States Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02142 United States Institute for Electronics and Nanotechnology Georgia Institute of Technology AtlantaGA30332 United States TEL Technology Center America LLC 255 Fuller Rd. AlbanyNY12203 United States Department of Condensed Matter Physics Faculty of Mathematics and Physics Charles University Ke Karlovu 5 Prague12116 Czech Republic Izentis LLC PO Box 397002 CambridgeMA02139 United States School of Materials Science and Engineering Georgia Institute of Technology AtlantaGA30332 United States Departamento de Ciencias Físicas Universidad Andres Bello Santiago837-0136 Chile Department of Chemical Engineering and Materials Science University of Southern California Los AngelesCA90089 United States Institute of Semiconductors and Microsystems TU Dresden Dresden Germany Department of Electrical Engineering and Computer Sciences University of California BerkeleyCA94720 United States

Crystalline materials with broken inversion symmetry can exhibit a spontaneous electric polarization, which originates from a microscopic electric dipole moment. Long-range polar or anti-polar order of such permanent dipoles gives rise to ferroelectricity or antiferroelectricity, respectively. However, the recently discovered antiferroelectrics of fluorite structure (HfO2 and ZrO2) are different: A non-polar phase transforms into a polar phase by spontaneous inversion symmetry breaking upon the application of an electric field. Here, we show that this structural transition in antiferroelectric ZrO2gives rise to a negative capacitance, which is promising for overcoming the fundamental limits of energy efficiency in electronics. Our findings provide insight into the thermodynamically 'forbidden' region of the antiferroelectric transition in ZrO2and extend the concept of negative capacitance beyond ferroelectricity. This shows that negative capacitance is a more general phenomenon than previously thought and can be expected in a much broader range of materials exhibiting structural phase transitions. Copyright © 2021, The Authors. All rights reserved.

关键词： Electric fields

A general framework for scintillation in nanophotonics

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arXiv 2021年

作者： Roques-Carmes, Charles Rivera, Nicholas Ghorashi, Ali Kooi, Steven E. Yang, Yi Lin, Zin Beroz, Justin Massuda, Aviram Sloan, Jamison Romeo, Nicolas Yu, Yang Joannopoulos, John D. Kaminer, Ido Johnson, Steven G. Soljačić, Marin Research Laboratory of Electronics MIT CambridgeMA02139 United States Department of Physics MIT CambridgeMA02139 United States Institute for Soldier Nanotechnologies MIT CambridgeMA02139 United States Department of Mathematics MIT CambridgeMA02139 United States Microsystems Technology Laboratories MIT CambridgeMA02139 United States Raith America Inc. United States Department of Electrical and Computer Engineering Technion Haifa32000 Israel

Bombardment of materials by high-energy particles (e.g., electrons, nuclei, X- and γ-ray photons) often leads to light emission, known generally as scintillation. Scintillation is ubiquitous and enjoys widespread applications in many areas such as medical imaging, X-ray non-destructive inspection, night vision, electron microscopy, and high-energy particle detectors. A large body of research focuses on finding new materials optimized for brighter, faster, and more controlled scintillation. Here, we develop a fundamentally different approach based on integrating nanophotonic structures into scintillators to enhance their emission. To start, we develop a unified and ab initio theory of nanophotonic scintillators that accounts for the key aspects of scintillation: the energy loss by high-energy particles, as well as the light emission by non-equilibrium electrons in arbitrary nanostructured optical systems. This theoretical framework allows us, for the first time, to experimentally demonstrate nearly an order-of-magnitude enhancement of scintillation, in both electron-induced, and X-ray-induced scintillation. Our theory also allows the discovery of structures that could eventually achieve several orders-of-magnitude scintillation enhancement. The framework and results shown here should enable the development of a new class of brighter, faster, and higher-resolution scintillators with tailored and optimized performances − with many potential applications where scintillators are used. Copyright © 2021, The Authors. All rights reserved.

关键词： Scintillation counters