Article
Nanoscience & Nanotechnology
Xin Tang, Jiawei Lai, H. Sepehri-Amin, T. Ohkubo, K. Hono
Summary: The study found that Pr-Fe-B and (Pr0.75Ce0.25)-Fe-B based hot-deformed magnets exhibit high magnetic performance at low temperatures, including large remanence and high coercivity, making them suitable as low-cost permanent magnet materials for cryogenic applications.
SCRIPTA MATERIALIA
(2021)
Article
Nanoscience & Nanotechnology
Kwangjae Park, Yusuke Hirayama, Jian Wang, Makoto Kobashi
Summary: This study demonstrates the preparation of Sm-Co bulk magnet with remarkable coercivity, excellent temperature coefficient, and thermal stability through the use of unique Sm-Co alloy nanopowder.
SCRIPTA MATERIALIA
(2022)
Article
Optics
Maximilian Pallmann, Timon Eichhorn, Julia Benedikter, Bernardo Casabone, Thomas Huemmer, David Hunger
Summary: Open-access microcavities are a powerful tool for enhancing light-matter interactions in solid-state quantum and nano systems and are crucial for advancing quantum technologies. To meet the conflicting requirements of full tunability and high stability, we have developed a fully-tunable, open-access, fiber-based Fabry-P\'erot microcavity platform that can operate in cryogenic environments with increased noise levels. The platform provides high finesse and small mode volume, allowing for strong enhancement of light-matter interactions and enabling experiments with a wide range of quantum and nano materials.
Article
Energy & Fuels
Ran Zhang, Lianxue Gao
Summary: This study focuses on the design technology of direct drive permanent magnet synchronous wind turbine, especially the semi-direct drive permanent magnet synchronous wind turbine. The power factor of the generator is improved by adding reactive power compensation device and filter circuit. The cogging torque and resistance torque of the generator are weakened by using the closed slot scheme and T-shaped rotor pole structure. The optimal design scheme is determined through comparative analysis.
Article
Mathematics
Mislav Trbusic, Anton Hamler, Viktor Gorican, Marko Jesenik
Summary: The paper presents a contactless detection method for determining the position of a rod permanent magnet within a ferrofluid. The proposed approach is based on the solenoidal nature of the field lines. Numerical evaluation showed promising results, indicating the potential practical application of the technique. Compared to other techniques such as X-ray or Vernier-caliper-based methods, the proposed method is more suitable for applications where simplicity and robustness are crucial.
Article
Engineering, Electrical & Electronic
Filip Zec, Jasna Dragosavac, Milos Radovic
Summary: This paper presents a method for on-site post-assembly magnetization of rare-earth PMG by applying DC current to its stator windings. The technique allows magnetization without removing the PMG from the main rotor shaft, reducing generator overhaul duration and costs. The process is validated through a case study in a real power plant, demonstrating successful magnetization of a 35 kVA rated power PMG. Subsequent simulation is performed to determine unknown parameters of the equipment used.
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS
(2021)
Article
Nanoscience & Nanotechnology
Ty Christoff-Tempesta, Yukio Cho, Dae-Yoon Kim, Michela Geri, Guillaume Lamour, Andrew J. Lew, Xiaobing Zuo, William R. Lindemann, Julia H. Ortony
Summary: The study introduces a small-molecule platform called aramid amphiphile, which exhibits stability and can self-assemble in water to form nanoribbons with high strength and toughness. These nanoribbons can be further organized into dry threads that can support 200 times their weight, extending small-molecule self-assembly to macroscopic materials and enabling new possibilities for solid-state applications.
NATURE NANOTECHNOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Cheng Zhou, Qi-Bin Ye, Jun Hu, Tan Zhao, Xiu-Hua Gao, Zhao-Dong Wang
Summary: This study investigates the role of lamellarization on the fraction and distribution of retained austenite in low-carbon multi-alloyed steel and its effects on mechanical properties. Adding an L-step in the process significantly increases the fraction of retained austenite, improving the material's ductility and strengthening mechanisms. Additionally, the dispersion of nanoscale vanadium carbides in multi-step heat treatment effectively enhances strength without compromising low-temperature toughness.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Wilhelm Kirchgaessner, Oliver Wallscheid, Joachim Boecker
Summary: In this study, deep recurrent and convolutional neural networks with residual connections were evaluated for predicting high-dynamic temperatures inside permanent magnet synchronous motors. It was found that these models showed strong estimation performance at minimal model sizes without requiring domain expertise or specific drive train specifications. The results indicate that these models can match the performance of classic thermodynamics-based approaches in terms of mean squared error and maximum absolute deviation.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Chemistry, Analytical
David Roma-Dollase, Vivek Gualani, Martin Gohlke, Klaus Abich, Jordan Morales, Alba Gonzalvez, Victor Martin, Juan Ramos-Castro, Josep Sanjuan, Miquel Nofrarias
Summary: High precision temperature measurements are essential in various physical experiments, particularly in space-borne gravitational wave detectors. This study presents a design capable of achieving 1 μK√Hz in most of the measuring band down to 1 mHz, and reaching N/20 μK√Hz at 0.1 mHz. The design involves resistive sensors in a Wheatstone bridge configuration with AC modulation to minimize noise. Additionally, a test bench is designed to ensure high stability environment for measurements, and experimental results are provided to characterize the test bench and the read-out, along with the discussion of potential noise sources.
Article
Chemistry, Multidisciplinary
Pierre Moritz, Antoine Gonon, Thomas Blon, Nicolas Ratel-Ramond, Fabrice Mathieu, Pierre Farger, Juan-Manuel Asensio-Revert, Simon Cayez, David Bourrier, Daisuke Saya, Liviu Nicu, Guillaume Viau, Thierry Leichle, Lise-Marie Lacroix
Summary: This study presents a versatile approach for the fabrication and direct integration of nanostructured magnetic materials onto silicon substrates, using magnetophoresis-assisted capillary assembly to create high-performance magnets and supercrystals. Sub-millimeter and self-standing magnets with magnetic properties comparable to NdFeB-based composites were obtained through this cost- and time-efficient process. The proof-of-concept of electromagnetically actuating a MEMS cantilever with these supercrystals highlights their potential as efficient integrated magnetic materials in portable devices.
Article
Chemistry, Multidisciplinary
Peng Sun, Shan Mei, Jiang-Fei Xu, Xi Zhang
Summary: The study developed a novel bio-based supramolecular adhesive (BSA) using renewable resources, which exhibited outstanding adhesion performance and excellent multi-reusability. By optimizing the material combination and interactions, the BSA achieved high adhesion strength at both ambient and cryogenic temperatures.
Article
Engineering, Electrical & Electronic
E. Catapano, A. Apra, M. Casse, F. Gaillard, S. de Franceschi, T. Meunier, M. Vinet, G. Ghibaudo
Summary: This study characterizes the electrical properties of FD-SOI five-gate qubit MOS devices and successfully models their performance using the Lambert-W function. The results demonstrate the applicability of this function even at deep cryogenic temperatures and its ability to accurately reproduce the device characteristics.
SOLID-STATE ELECTRONICS
(2022)
Article
Chemistry, Multidisciplinary
Garnet Cameron, Jonathan Cuevas, Jeffrey Pound, David Shiner
Summary: Atomic state preparation benefits from a compact and uniform magnetic field source, which is applied successfully to optical pumping of atomic helium. The source features a configured assembly of customized annular magnets, leading to a greater than 50% clear aperture with a uniform and collimated magnetic field.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Michal Vidlak, Pavol Makys, Lukas Gorel
Summary: This paper proposes a novel constant power factor loop in the V/f control strategy for a permanent magnet synchronous motor (PMSM). The advantage of this algorithm is its independence of machine parameters and its low-cost and simple implementation as a sensorless solution. The proposed strategy is compared to traditional sensorless FOC with a higher requirement for microcontroller unit (MCU) performance.
APPLIED SCIENCES-BASEL
(2022)
Article
Multidisciplinary Sciences
J. Yoneda, W. Huang, M. Feng, C. H. Yang, K. W. Chan, T. Tanttu, W. Gilbert, R. C. C. Leon, F. E. Hudson, K. M. Itoh, A. Morello, S. D. Bartlett, A. Laucht, A. Saraiva, A. S. Dzurak
Summary: The article demonstrates high-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon, with a reported polarization transfer fidelity of 99.97% and an average coherent transfer fidelity of 99.4%. The results suggest that this method can reduce the cost of fault-tolerant quantum processors and provide key elements for high-fidelity, on-chip quantum information distribution.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Multidisciplinary
Alexander M. Jakob, Simon G. Robson, Vivien Schmitt, Vincent Mourik, Matthias Posselt, Daniel Spemann, Brett C. Johnson, Hannes R. Firgau, Edwin Mayes, Jeffrey C. McCallum, Andrea Morello, David N. Jamieson
Summary: This study discusses the material choice of silicon chips containing arrays of single dopant atoms for classical and quantum devices, as well as the method of near-surface implantation of single ions and the associated physics model and limiting factors.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
Mateusz T. Madzik, Serwan Asaad, Akram Youssry, Benjamin Joecker, Kenneth M. Rudinger, Erik Nielsen, Kevin C. Young, Timothy J. Proctor, Andrew D. Baczewski, Arne Laucht, Vivien Schmitt, Fay E. Hudson, Kohei M. Itoh, Alexander M. Jakob, Brett C. Johnson, David N. Jamieson, Andrew S. Dzurak, Christopher Ferrie, Robin Blume-Kohout, Andrea Morello
Summary: This study demonstrates universal quantum logic operations using nuclear spins in a silicon nanoelectronic device, achieving high-fidelity entangled states. The precise characterization of quantum operations shows that nuclear spins are approaching the performance required for fault-tolerant quantum processors. Additionally, the entanglement between nuclear spins and electron spins is also demonstrated. The results establish a viable route for scalable quantum information processing using donor nuclear and electron spins.
Article
Physics, Applied
Daniel J. Parker, Mykhailo Savytskyi, Wyatt Vine, Arne Laucht, Timothy Duty, Andrea Morello, Arne L. Grimsmo, Jarryd J. Pla
Summary: Degenerate parametric amplifiers (DPAs) exhibit phase-sensitive gain and have been utilized in various applications. This study investigates a microwave DPA utilizing nonlinearity from kinetic inductance with high dynamic range and squeezing potential. The amplifier shows promising performance near quantum noise limit and minimal higher-order nonlinearities, making it a potential candidate for future applications.
PHYSICAL REVIEW APPLIED
(2022)
Article
Multidisciplinary Sciences
Stephan G. J. Philips, Sergey Amitonov, Sander L. de Snoo, Maximilian Russ, Nima Kalhor, Christian Volk, William I. L. Lawrie, Delphine Brousse, Larysa Tryputen, Brian Paquelet Wuetz, Amir Sammak, Menno Veldhorst, Giordano Scappucci, Lieven M. K. Vandersypen
Summary: Future quantum computers require a large number of reliable qubits, but this is typically conflicting with high fidelity operations. In this study, a six-qubit processor was designed and operated with high fidelities for universal operation, state preparation, and measurement, using careful Hamiltonian engineering and efficient calibration. These advances are a major stepping stone towards large-scale quantum computers.
Article
Physics, Multidisciplinary
Mark A. Johnson, Mateusz T. Madzik, Fay E. Hudson, Kohei M. Itoh, Alexander M. Jakob, David N. Jamieson, Andrew Dzurak, Andrea Morello
Summary: This article presents a method for initializing quantum states with a fidelity beyond the thermal limit using real-time monitoring and negative-result measurement. The experimental results show that this method can reduce initialization errors and improve fidelity by increasing the bandwidth of the amplifier chain or slowing down electron tunneling rates.
Article
Physics, Applied
S. G. Robson, P. Raecke, A. M. Jakob, N. Collins, H. R. Firgau, V Schmitt, V Mourik, A. Morello, E. Mayes, D. Spemann, D. N. Jamieson
Summary: This study explores a feasible approach to create large-scale donor arrays in silicon devices by implanting low-energy ions and evaluating the device response characteristics using a specific characterization system.
PHYSICAL REVIEW APPLIED
(2022)
Article
Chemistry, Multidisciplinary
Zeheng Wang, MengKe Feng, Santiago Serrano, William Gilbert, Ross C. C. Leon, Tuomo Tanttu, Philip Mai, Dylan Liang, Jonathan Y. Huang, Yue Su, Wee Han Lim, Fay E. Hudson, Christopher C. Escott, Andrea Morello, Chih Hwan Yang, Andrew S. Dzurak, Andre Saraiva, Arne Laucht
Summary: This study investigates the potential of elongated quantum dots, known as jellybean quantum dots, as qubit-qubit couplers. Through experimental measurements and simulations, it is found that under low electron occupancies, the jellybean quantum dots form a tunable, artificial molecule composed of three coupled dots. Under high electron occupancies, they merge into one large dot with well-defined spin states, demonstrating the potential of jellybean dots as qubit couplers in future quantum computing architectures.
ADVANCED MATERIALS
(2023)
Article
Physics, Applied
C. T. -K. Lew, V. K. Sewani, N. Iwamoto, T. Ohshima, J. C. Mccallum, B. C. Johnson
Summary: Spin defects in solid-state sensors are investigated for their magnetic sensitivity, with potential applications in various industries. The study utilizes a silicon carbide pn-junction diode to detect a spin defect ensemble and enhance the baseline sensitivity through the hyperfine-induced spin-mixing effect observed at zero magnetic field. Additional electron-hole pairs are generated through above bandgap optical excitation, and a balanced detection scheme is implemented to reject common-mode noise, achieving an ultimate sensitivity of 30 nT/root Hz. Both techniques greatly enhance the magnetic sensitivity of the device by a total factor of approximately 24, paving the way for sub-nanotesla magnetic field sensitivities with electrical detection.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Philip Daniel Blocher, Serwan Asaad, Vincent Mourik, Mark A. Johnson, Andrea Morello, Klaus Molmer
Summary: Out-of-time-ordered correlation functions (OTOCs) are crucial in studying quantum information scrambling, but are difficult to measure experimentally. This study proposes an OTOC measurement protocol that does not rely on time reversal and is applicable to various experimental settings and systems.
Review
Physics, Applied
Anasua Chatterjee, Paul Stevenson, Silvano De Franceschi, Andrea Morello, Nathalie P. de Leon, Ferdinand Kuemmeth
Summary: This review discusses the implementation of semiconductor qubits in various quantum applications and highlights their potential in advancing quantum simulation, computation, sensing, and communication. It describes the advancements in semiconductor charge and spin qubits and emphasizes their role as leading contenders for large-scale quantum circuits. The review aims to provide a technical introduction for non-specialists and serve as a forward-looking reference for scientists entering the field.
NATURE REVIEWS PHYSICS
(2021)
Article
Quantum Science & Technology
Amanda E. Seedhouse, Tuomo Tanttu, Ross C. C. Leon, Ruichen Zhao, Kuan Yen Tan, Bas Hensen, Fay E. Hudson, Kohei M. Itoh, Jun Yoneda, Chih Hwan Yang, Andrea Morello, Arne Laucht, Susan N. Coppersmith, Andre Saraiva, Andrew S. Dzurak
Summary: The study discusses the importance of measuring qubits for quantum computation and error correction, introducing different types of blockade readout methods. Through experiments and theoretical models, the study explores the crossover point between parity and singlet-triplet readout, as well as the underlying physics mechanisms.
