Gilbert damping in the layered antiferromagnet CrCl_(3)

We theoretically and experimentally studied the Gilbert damping evolution of both acoustic and optical magnetic resonance modes in the layered flake Cr Cl;with an external magnetic field H applied in plane.Based on a Lagrangian equation and a Rayleigh dissipation function,we predicted that the resonance linewidth△H as a function of microwave frequencyωis nonlinear for both acoustic and optical modes in the Cr Cl;flake,which is significantly different from the linear relationship of△H-ωin ferromagnets.Measuring the microwave transmission through the Cr Cl;flake,we obtained theω–H dispersion and damping evolution△H–ωfor both acoustic and optical modes.Combining both our theoretical prediction and experimental observations,we concluded that the nonlinear damping evolution△H–ωis a consequence of the interlayer interaction during the antiferromagnetic resonance,and the interlayer Gilbert dissipation plays an important role in the nonlinear damping evolution because of the asymmetry of the non-collinear magnetizaiton between layers.

Improved non-uniform subdivision scheme with modified Eigen-polyhedron

In this study,a systematic refinement method was developed for non-uniform Catmull-Clark subdivision surfaces to improve the quality of the surface at extraordinary points(EPs).The developed method modifies the eigenpolyhedron by designing the angles between two adjacent edges that contain an EP.Refinement rules are then formulated with the help of the modified eigenpolyhedron.Numerical experiments show that the method significantly improves the performance of the subdivision surface for non-uniform parameterization.

Reachable set estimation for discrete-time Markovian jump neural networks with unified uncertain transition probability

This paper focuses on the reachable set estimation for Markovian jump neural networks with time delay.By allowing uncertainty in the transition probabilities,a framework unifies and enhances the generality and realism of these systems.To fully exploit the unified uncertain transition probabilities,an equivalent transformation technique is introduced as an alternative to traditional estimation methods,effectively utilizing the information of transition probabilities.Furthermore,a vector Wirtinger-based summation inequality is proposed,which captures more system information compared to existing ones.Building upon these components,a novel condition that guarantees a reachable set estimation is presented for Markovian jump neural networks with unified uncertain transition probabilities.A numerical example is illustrated to demonstrate the superiority of the approaches.

新型磁电阻探索与多态数据存储应用

随着现代信息存储与通信技术的快速发展,人们希望新型的电子器件能兼具低功耗、非易失、高密度等优异性能,甚至能实现信息的存储、处理与通信三位一体的功能,因而对材料和器件的研究提出了巨大的挑战.为满足上述需求,我们课题组一方面在多种新材料和器件中探索新的磁电阻效应,深入理解自旋相关输运的物理机理,进而获得有效调控自旋相关输运的新途径;另一方面,基于多物理效应调控材料和器件的磁电阻,进而获得可用于多态信息存储的自旋电子学原型器件.在新型磁电阻探索方面,本文将介绍非晶浓磁半导体的负磁电阻、单晶CoZnO磁性半导体硬带跃迁区的正磁电阻、非磁肖特基异质结中的新型整流磁电阻以及非对称势垒磁性隧道结中的隧穿整流磁电阻.在多态数据存储方面,本文将介绍氧化物异质结中可用电磁场调控的4电阻态、磁性异质结中基于剩磁调控的10电阻态以及磁性单层膜中基于自旋轨道矩效应的10电阻态.

腔内自旋与微波相互作用的电检测

聚焦界面自旋动力学和自旋传输特性,自旋电子学发展针对自旋产生、探测、调控的技术方法,为自旋电子器件的开发提供了物理基础,是自旋电子学研究的根本任务.借鉴腔量子电动力学的思想和方法,在微波谐振腔内实现室温下的磁子-微波强耦合,为实现信息和能量在自旋与电磁波之间的相干传输提供了可能,同时为调控自旋提供了新方法.本文简要介绍了磁子-微波耦合的概念和机制,梳理了这一方向的发展脉络,重点介绍了磁子-微波强耦合中电检测技术及其产生的自旋流的特性.

Amorphous nonstoichiometric oxides with tunable room-temperature ferromagnetism and electrical transport

Material functionalities strongly depend on the stoichiometry,crystal structure,and homogeneity.Here we demonstrate an approach of amorphous nonstoichiometric inhomogeneous oxides to realize tunable ferromagnetism and electrical transport at room temperature.In order to verify the origin of the ferromagnetism,we employed a series of structural,chemical,and electronic state characterizations.Combined with electron microscopy and transport measurements,synchrotron-based grazing incident wide angle X-ray scattering,soft X-ray absorption and circular dichroism clearly reveal that the roomtemperature ferromagnetism originates from the In0.23Co0.77O1-v,amorphous phase with a large tunable range of oxygen vacancies.The room-temperature ferromagnetism is tunable from a high saturation magnetization of 500 emu cm-3 to below 25 emu cm-3,with the evolving electrical resistivity from5×103μΩ cm to above 2.5×105 μΩ cm.Inhomogeneous nano-crystallization emerges with decreasing oxygen vacancies,driving the system towards non-ferromagnetism and insulating regime.Our work unfolds the novel functionalities of amorphous nonstoichiometric inhomogeneous oxides,which opens up new opportunities for developing spintronic materials with superior magnetic and transport properties.

CORNER-CUTTING SUBDIVISION SURFACES OF GENERAL DEGREES WITH PARAMETERS

As a corner-cutting subdivision scheme,Lane-Riesefeld algorithm possesses the concise and unified form for generating uniform B-spline curves:vertex splitting plus repeated midpoint averaging.In this paper,we modify the second midpoint averaging step of the Lane-Riesefeld algorithm by introducing a parameter which controls the size of corner cutting,and generalize the strategy to arbitrary topological surfaces of general degree.By adjusting the free parameter,the proposed method can generate subdivision surfaces with flexible shapes.Experimental results demonstrate that our algorithm can produce subdivision surfaces with comparable or even better quality than the other state-of-the-art approaches by carefully choosing the free parameters.