Article
Physics, Multidisciplinary
B. Stoddart-Stones, X. Montiel, M. G. Blamire, J. W. A. Robinson
Summary: Superconducting spintronics aims to enhance the performance of spintronics-based devices by utilizing the interaction between magnetic order and superconductivity. In this study, the authors experimentally investigate a superconducting spin valve and observe a crossover from giant magnetoresistance to the superconducting spin-valve effect as the thickness of the material changes.
COMMUNICATIONS PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Rudolf Smorka, Pavel Balaz, Michael Thoss, Martin Zonda
Summary: In this study, we investigated the spin dynamics and spin-transfer torque in a spin valve under bias voltage using a hybrid quantum-classical equation of motion approach. We found that the interaction between localized classical magnetic moments and conduction electrons results in a complex effective exchange coupling between the magnetic layers, leading to a deviation of magnetizations from their anisotropy axes even in equilibrium. The introduction of a finite bias voltage triggers spin currents and spin-transfer torques, which further tilt the magnetizations and govern the relaxation processes of the spin dynamics. By analyzing different scenarios of the applied bias voltage, we observed that symmetric and asymmetric voltage drops can cause relaxation times of the spin dynamics to differ by several orders of magnitude at comparable charge currents. In both cases, resonant features were observed, where the relaxation was enhanced whenever the chemical potential of the leads matched the maxima in the density of the states of the spin-valve electrons.
Article
Physics, Applied
Andrei Azovtsev, Nikolay A. Pertsev
Summary: Acoustic excitation is an attractive tool for generating spin dynamics in magnetoelastic materials. In this study, we theoretically describe the magnetization dynamics and spin flow induced by acoustic waves in trilayer structures. Our results show that the acoustic waves cause inhomogeneous magnetization precession, oscillating spin current, and spin accumulation in the spacer.
PHYSICAL REVIEW APPLIED
(2022)
Article
Physics, Applied
M. Haidar, H. Mazraati, P. Durrenfeld, H. Fulara, M. Ranjbar, J. Akerman
Summary: The magnetodynamic and auto-oscillation properties of Ni 100 - xFe(x)/Pt (x=10-40) nanoconstriction-based spin Hall nano-oscillators were significantly influenced by compositional effects, with increasing Fe content leading to lower damping and spin Hall efficiency, requiring higher current densities for spin-wave auto-oscillations at higher microwave frequencies. This underscores the critical role of compositional effects in engineering spin Hall devices for microwave and magnonic applications.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Ya-Ru Wang, Zheng-Chuan Wang, Gang Su
Summary: The spinor Boltzmann equation beyond gradient approximation in a ferromagnetic metal with a single domain wall is derived, along with the charge continuity equation and spin diffusion equation. A generalized spin transfer torque (STT) is obtained using the spin diffusion equation, extending the usual STT to cases beyond gradient approximation and with inhomogeneous current. Numerical calculations are performed for physical observables, and the motion of domain walls and critical electric fields are studied using the Landau-Lifshitz-Gilbert-Slonczewski equation.
Article
Materials Science, Multidisciplinary
Haoshen Ye, Lisha Liu, Dongmei Bai, G. P. Zhang, Junting Zhang, Jianli Wang
Summary: In this study, the spin valve effect in the TiCr2N4 monolayer was investigated using density functional theory and Boltzmann transport theory. The results showed that the TiCr2N4 monolayer retains a ferromagnetic ground state above room temperature, and its electrical transport property is strongly dependent on the angle of magnetization direction. The large difference in conductivity between the TiCr2N4 monolayers with parallel and anti-parallel magnetization leads to giant magnetoresistance.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Physical
Shuaishuai Ding, Yuan Tian, Xiang Liu, Ye Zou, Huanli Dong, Wenbo Mi, Wenping Hu
Summary: This study highlights the significant role of Fe(3)O(4) electrode in Fe3O4/P3HT/Co polymer spin valves, particularly near the Verwey transition temperature. The first-order metal-insulator transition in Fe(3)O(4) has a dramatic effect on the magnetoresistance enhancement of polymer spin valves.
Article
Physics, Applied
Vadym Iurchuk, Julien Bran, Manuel Acosta, Bohdan Kundys
Summary: Electric-field control of magnetism using the inverse magnetostrictive effect is a promising approach for improving energy-efficient storage and sensing devices that rely on the giant magnetoresistance effect. In this study, we demonstrate the modulation of magnetotransport properties in a Co/Cu/Py pseudo spin valve grown on a ferroelectric substrate using a lateral electric field. The decrease in the giant magnetoresistance ratio is attributed to strain-induced deviation of the Co layer's magnetization. We also show that strain-induced magnetic anisotropy can effectively shift the switching field of the magnetostrictive Co layer, offering potential for enhancing magnetic switching in spintronic devices.
APPLIED PHYSICS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Mengli Liu, Wei Du, Hua Su, Huaiwu Zhang, Bo Liu, Hao Meng, Xiaoli Tang
Summary: Pure voltage-controlled magnetism is the focus of next-generation ultralow power consumption spintronic devices, and this research demonstrates nonvolatile and stable magnetization switching using voltage impulses in a spin-valve multiferroic heterostructure. In addition, a significant reduction in the critical magnetic field required for complete 180 degrees magnetization reversal of the free layer was achieved, indicating the feasibility of E-field-assisted energy-efficient in-plane magnetization switching.
NPG ASIA MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Ling Zhou, Junwei Huang, Ming Tang, Caiyu Qiu, Feng Qin, Caorong Zhang, Zeya Li, Di Wu, Hongtao Yuan
Summary: Magnetic tunnel junctions (MTJs) are spintronic devices based on the spin valve effect, and can be improved by utilizing advanced 2D ferromagnetic materials or exploring the gate-tunable magnetic properties. Recent research has shown that gate-tunable MTJ devices can be achieved by electrolyte gating, allowing for adjustable magnetoresistance ratio and magnetoresistance switching strength.
Article
Physics, Applied
Ziwei Wang, Di Wang, Long Liu, Sheng Jiang, Guozhi Chai, Jiangwei Cao, Guozhong Xing
Summary: This study introduces a novel type of all-electrical compact STNOs utilizing tilted magnetic anisotropy (TMA) for frequency modulation. By incorporating tunable TMA in the ferromagnetic reference layer, precise modulation of oscillation frequency ranging from 495 to 556 MHz is achieved. The research also demonstrates how oscillation frequency modulation can be achieved by adjusting the current intensity and TMA angle.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Nityananda Acharyya, Vaishnavi Sajeev, Shreeya Rane, Subhajit Karmakar, Dibakar Roy Chowdhury
Summary: Metal-based magnetic multilayers are crucial for giant-magnetoresistance (GMR) in magnetic memory devices and spintronic applications. This study investigates the magnetoresistive effect in Al/Ni/Al/Ni/Al spin valve structures using contactless terahertz (THz) spectroscopy. The results demonstrate magnetic field-dependent conductivity enhancement in the multilayers, showing potential for low power THz magnetism and dynamically controllable THz devices.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Xiaomin Cui, Shaojie Hu, Takashi Kimura
Summary: By reducing the lateral dimension of the nonmagnetic spin channel, the spin accumulation signal in lateral spin valves can be effectively enhanced. The temperature dependence of the spin accumulation signal and the influence of thermal spin injection under high bias current are also discussed.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Deying Xia, Ying-Bing Jiang, John Notte, Doug Runt
Summary: This study compares the usage of a neon focused ion beam with the traditional gallium focused ion beam for milling GaAs material, finding that neon FIB produces less undesired artifacts and subsurface damage at lower energies. Additionally, neon FIB can create trenches as small as 20 nm wide with high fidelity and minimal damage.
APPLIED SURFACE SCIENCE
(2021)
Article
Nanoscience & Nanotechnology
M. Najarsadeghi, A. Ahmadi Fouladi, A. Zati Rostami, A. Pahlavan
Summary: Using the non-equilibrium Green's function method and tight-binding Hamiltonian model, the spin-dependent transport and tunnel magnetoresistance (TMR) of AAA- and ABC-stacked trilayer zigzag graphene nanoribbon (TLG) connected to two ferromagnetic (FM) single-layer zigzag graphene nanoribbons (FM/TLG/FM system) were theoretically investigated. Results showed that the TMR for both AAA- and ABC-stacked cases could be increased about 100% due to the band-selective rule, and the magnitude of this 100% TMR region enhanced with the increase of the magnetization strength in FM graphene nanoribbon electrodes. The TLG dimension also had a prominent effect on the TMR ratio of the system.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2022)
Article
Optics
Peng Dai, Yasi Wang, Yueqiang Hu, C. H. de Groot, Otto Muskens, Huigao Duan, Ruomeng Huang
Summary: This study demonstrates the reverse design of F-P cavity structure using deep learning, which enables the production of a wide color space coverage over 215% of sRGB with high accuracy. Compared to evolutionary algorithms, neural networks show significant improvement in design efficiency, highlighting the potential of deep learning in achieving extremely accurate design of nanostructured color filters.
PHOTONICS RESEARCH
(2021)
Article
Energy & Fuels
Yuxiao Zhu, Daniel W. Newbrook, Peng Dai, C. H. Kees de Groot, Ruomeng Huang
Summary: This study demonstrates the application of artificial neural network, a deep learning technique, in forward modeling the maximum power generation and efficiency of a thermoelectric generator for the first time. The neural networks, with the coupling of genetic algorithm, can optimize the geometrical structure of the generator quickly and accurately, providing a new and cost-effective approach for system level design and optimization of thermoelectric generators and other energy harvesting technologies.
Article
Physics, Condensed Matter
Tahsin Ashraf Khan, Patrick A. Burr, David Payne, Mattias Juhl, Utshash Das, Brett Hallam, Darren Bagnall, Binesh Puthen Veettil
Summary: Research using molecular dynamics simulations shows that directional microwave heating of a SiC crystal slab along specific crystallographic directions results in significantly faster melting when the electric field is applied parallel to the surface compared to perpendicular application.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
Y. J. Noori, S. Thomas, S. Ramadan, V. K. Greenacre, N. M. Abdelazim, Y. Han, J. Zhang, R. Beanland, A. L. Hector, N. Klein, G. Reid, P. N. Bartlett, C. H. de Groot
Summary: This paper presents a method for preparing two-dimensional heterostructures on graphene electrodes using electrodeposition technique. By selectively depositing transition metal dichalcogenides on micro-electrodes, uniform layers of WS2 can be grown controllably. This technique paves the way for large-scale production of two-dimensional material heterostructures.
Article
Nanoscience & Nanotechnology
Peng Dai, Kai Sun, Xingzhao Yan, Otto L. Muskens, C. H. (Kees) de Groot, Xupeng Zhu, Yueqiang Hu, Huigao Duan, Ruomeng Huang
Summary: The study solved the one-to-many problem by employing a conditional generative adversarial network to generate multiple solution groups, allowing for the selection of the best design for each color and achieving a high level of accuracy.
Article
Nanoscience & Nanotechnology
Kai Sun, Wei Xiao, Callum Wheeler, Mirko Simeoni, Alessandro Urbani, Matteo Gaspari, Sandro Mengali, C. H. (Kees) de Groot, Otto L. Muskens
Summary: This study demonstrates a visually transparent, smart radiator panel with reduced solar absorption using high-quality VO2 thin films and plasmonic enhancement effects. It offers a new approach for thermal management in applications requiring visual transparency.
Article
Nanoscience & Nanotechnology
Omesh Kapur, Dongkai Guo, Jamie Reynolds, Yisong Han, Richard Beanland, Liudi Jiang, C. H. (Kees) de Groot, Ruomeng Huang
Summary: A memristor based on silicon carbide (SiC) has been developed, showing excellent binary resistive switching and the ability to emulate various synaptic functions. The conductance of this memristor can be modulated through the application of different signals, successfully replicating the synaptic function of learning-forgetting-relearning processes.
ADVANCED ELECTRONIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Peng Dai, Kai Sun, Otto L. Muskens, C. H. de Groot, Ruomeng Huang
Summary: Dynamic structural color provides a time dimension to enhance information load and functionality. This study presents the inverse design of a dynamic structural color asymmetric Fabry-Perot cavity using parameter-based conditional generative adversarial networks. The designed structure achieves a large gamut and color coverage variation through the phase change of a VO2 layer.
OPTICAL MATERIALS EXPRESS
(2022)
Article
Materials Science, Multidisciplinary
Kai Sun, Evangelos Vassos, Xingzhao Yan, Callum Wheeler, James Churm, Peter R. Wiecha, Simon A. Gregory, Alex Feresidis, Cornelis H. de Groot, Otto L. Muskens
Summary: This study demonstrates a large-scale aluminum zinc oxide metasurface coating based on deep-UV lithography, which can achieve a wide range of dual-band reflectivity values and brings commercially relevant and scalable technology closer to infrared metasurface coatings.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Kai Sun, Callum Wheeler, James A. Hillier, Sheng Ye, Ioannis Zeimpekis, Alessandro Urbani, Nikolaos Kalfagiannis, Otto L. Muskens, Cornelis H. (Kees) de Groot
Summary: The unique structural transition of VO2 between dielectric and metallic phases has significant potential in optical and electrical applications. This study presents a W:VO2 process based on atomic layer deposition (ALD) that enables precise control of W-doping and reduction of the phase transition temperature. The incorporation of W through ALD growth results in a state-of-the-art phase transition temperature and high emissivity contrast, making it suitable for the design of smart and switchable devices.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Ayoub H. Jaafar, Lingcong Meng, Tongjun Zhang, Dongkai Guo, Daniel Newbrook, Wenjian Zhang, Gillian Reid, C. H. de Groot, Philip N. Bartlett, Ruomeng Huang
Summary: We report the development of flexible memristor devices based on hybrid organic-inorganic materials using a fast and simple electrochemical fabrication method. These devices exhibit reliable and reproducible bipolar resistive switching at low voltages without the need for an electroforming process. Multistate switching behavior can also be achieved by controlling the compliance current.
ACS APPLIED NANO MATERIALS
(2022)
Article
Physics, Applied
Binesh Puthen Veettil, Yuchao Zhang, David Payne, Mattias Juhl, Shujuan Huang, Brett Hallam, Darren Bagnall
Summary: Microwave annealing, despite being poorly researched and underutilized in the semiconductor industry, possesses the potential to significantly reduce time and cost in large-volume semiconductor processing, specifically in the manufacturing of photovoltaic modules. This study examines microwave annealing of silicon solar cells, demonstrating its capability for efficient passivation of light-induced defects and mitigating light-induced degradation. Results indicate that microwave annealing produces comparable outcomes to rapid thermal annealing.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Yuxiao Zhu, Daniel W. Newbrook, C. H. de Groot, Ruomeng Huang
Summary: The market for Internet-of-things (IoT) with integrated wireless sensor networks is growing rapidly, creating a high demand for sustainable micro-Watt-scale power supplies. Radiative cooling (RC) combined with thermoelectric generator (TEG) offers a novel and sustainable energy source for energy harvesting. This work provides a comprehensive analysis of the RC-TEG concept through 3D finite element method simulation, investigating the impact of various parameters and demonstrating continuous power supply capability using real-time environmental data from Singapore and London.
JOURNAL OF PHYSICS-PHOTONICS
(2023)
Article
Chemistry, Multidisciplinary
Xiaohu Chen, Darren Bagnall, Noushin Nasiri
Summary: This study demonstrates that the application of ethanol can induce capillary forces on ZnO nanoclusters, leading to the formation of micro-scale islands and larger nanoparticles, thereby improving the robustness and quality of the layers without compromising their overall porosity, structural or optical properties. The enhanced electronic transport within the layers greatly improves the photoresponse of UV detectors. The use of ethanol and capillary force holds promise for improving the performance of nanostructured, ultra-porous devices with poor charge transport.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Optics
Wei Xiao, Peng Dai, H. Johnson Singh, Idris A. Ajia, Xingzhao Yan, Peter R. Wiecha, Ruomeng Huang, C. H. (Kees) de Groot, Otto L. Muskens, Kai Sun
Summary: This study utilizes a genetic algorithm and a transfer matrix method to design and optimize a multimaterial thin-film OSR for broadband radiative cooling. The optimized structure, consisting of 18 alternating layers of SiN, SiO2, and Ta2O5 on an Al mirror backreflector, exhibits low solar absorption and high broadband infrared emissivity. The fabricated OSR demonstrates good thermal-optical properties and achieves efficient net cooling power under one sun total solar irradiance in space.