Temperature dependence of spin pumping in YIG/NiOx/W multilayer

We report the temperature dependence of the spin pumping effect for Y₃Fe₅O₁₂ (YIG, 0.9 μm)/NiO (t_NiO)/W (6 nm) (t_NiO = 0 nm, 1 nm, 2 nm, and 10 nm) heterostructures. All samples exhibit a strong temperature-dependent inverse spin Hall effect (ISHE) signal I_c and sensitivity to the NiO layer thickness. We observe a dramatic decrease of I_c with inserting thin NiO layer between YIG and W layers indicating that the inserting of NiO layer significantly suppresses the spin transport from YIG to W. In contrast to the noticeable enhancement in YIG/NiO (t_NiO ≈ 1-2 nm)/Pt, the suppression of spin transport may be closely related to the specific interface-dependent spin scattering, spin memory loss, and spin conductance at the NiO/W interface. Besides, the I_c of YIG/NiO/W exhibits a maximum near the T_N of the AF NiO layer because the spins are transported dominantly by incoherent thermal magnons.     

Spin transport in epitaxial Fe3O4/GaAs lateral structured devices

Research in the spintronics community has been intensively stimulated by the proposal of the spin field-effect transistor (SFET), which has the potential for combining the data storage and process in a single device. Here we report the spin dependent transport on a Fe₃O₄/GaAs based lateral structured device. Parallel and antiparallel states of two Fe₃O₄ electrodes are achieved. A clear MR loop shows the perfect butterfly shape at room temperature, of which the intensity decreases with the reducing current, showing the strong bias dependence. Understanding the spin-dependent transport properties in this architecture has strong implication in further development of the spintronic devices for room-temperature SFETs.     

Large-Area Freestanding Weyl Semimetal WTe_2 Membranes

We report a universal transfer methodology for producing artificial heterostructures of large-area freestanding single-crystalline WTe₂ membranes on diverse target substrates.The transferred WTe₂ membranes exhibit a nondestructive structure with a carrier mobility comparable to that of as-grown films(～179–1055 cm²·V^?1·s^?1).Furthermore,the transferred membranes show distinct Shubnikov–de Haas quantum oscillations as well as weak localization/weak anti-localization.These results provide a new approach to the development of atom manufacturing and devices based on atomic-level,large-area topological quantum films.     

具有大磁各向异性和高居里温度的二维笼目磁性材料Fe3As

最近，对二维铁磁材料的研究已成为自旋电子器件领域的热点。本文通过自旋极化密度泛函理论计算，设计出一种新型的二维材料Fe₃As,其居里温度(T_c)为300 K,可达到室温。预测的二维Fe₃As具有很强的面内Fe—Fe耦合，其大的磁各向异性能量(MAE)大约为366.7μeV,有助于材料维持长程铁磁序。这种二维Fe₃As的能带同时具有平带和狄拉克点的特征。值得注意的是，平带的位置与磁耦合的强度正相关。此外，在双轴应变的作用下，随着平带和费米面之间的距离不断减小，T_c也在逐渐升高。因此，Fe₃As单层有望成为二维室温自旋电子学器件的一种有前途的候选材料。     

Experimental observation of interlayer perpendicular standing spin wave mode with low damping in skyrmion-hosting [Pt/Co/Ta]10 multilayer

An interlayer perpendicular standing spin wave mode is observed in the skyrmion-hosting [Pt/Co/Ta]₁₀ multilayer by measuring the time-resolved magneto-optical Kerr effect. The observed interlayer mode depends on the interlayer spin-pumping and spin transfer torque among the neighboring Co layers. This mode shows monotonically increasing frequency-field dependence which is similar to the ferromagnetic resonance mode, but within higher frequency range. Besides, the damping of the interlayer mode is found to be a relatively low constant value of 0.027 which is independent of the external field. This work expounds the potential application of the [heavy-metal/ferromagnetic-metal]_n multilayers to skyrmion-based magnonic devices which can provide multiple magnon modes, relatively low damping, and skyrmion states, simultaneously.     

Observation of Shubnikov-de Haas Oscillations in Large-Scale Weyl Semimetai WTe2 Films

Topological Weyl semimetal WTe2 with large-scale Him form has a promising prospect for new-generation spintronic devices.However,it remains a hard task to suppress the defect states in large-scale WTe2 films due to the chemical nature.Here we significantly improve the crystalline quality and remove the Te vacancies in WTe2 films by post annealing.We observe the distinct Shubnikov-de Haas quantum oscillations in WTe2 films.The nontrivial Berry phase can be revealed by Landau fan diagram analysis.The Hall mobility of WTe2 films can reach 1245cm^2V^-1s^-1 and 1423cm^2V^-1s^-1 for holes and electrons with the carrier density of 5× 10^19 cm^-3 and 2 × 10^19 cm^-3,respectively.Our work provides a feasible route to obtain high-quality Weyl semimetal films for the future topological quantum device applications.     

Magnetic Damping Properties of Single-Crystalline Co55Mn18Ga27 and Co50Mn18Ga32 Films

We investigate the structural,static magnetic and damping properties in two Mn-deficient magnetic Weyl semimetal Co-Mn-Ga(CMG) alloy films,i.e.,Co₅₅Mn₁₈Ga₂₇(CMG1) and Co₅₀Mn₁₈Ga₃₂(CMG2),which were epitaxially grown on MgO(001) substrates.CMG1 has a mixing phase of B₂ and L21,larger saturation magnetization(Ms ～760 emu/cm³),stronger in-plane magnetic anisotropy.CMG2 has an almost pure B₂ phase,small...     

水下结构状态观测中的悬浮杂质遮挡消除方法

水下结构状态视觉检测过程中，观测相机镜头易受到水体中枯叶、藻类等悬浮杂质遮挡，导致水下结构表观影像信息丢失，影响检测效果。针对该问题，利用水下视频序列中的帧内空间信息与帧间运动信息，提出一种悬浮杂质遮挡消除方法。根据相邻帧间的光流场分布信息，提出位移补偿策略，消除相机移动导致的帧间背景偏移；结合悬浮杂质成像特性，建立动态视觉感知模型，在对齐后的相邻帧基础上，实现不同形态悬浮杂质的准确检测；构建一种混合引导修复模型，确立帧间最优互补信息，还原悬浮杂质遮挡区域。在构建的真实与合成数据集上的测试结果表明，本文方法能够准确检测并消除悬浮杂质的遮挡，处理后的图像质量在多项指标上均得到明显提升。     

Manipulating Skyrmion Motion on a Nanotrack with Varied Material Parameters and Tilted Spin Currents

Magnetic skyrmions are topological quasiparticles with nanoscale size and high mobility, which have potential applications in information storage and spintronic devices. The manipulation of skyrmion’s dynamics in the track is an important topic due to the skyrmion Hall effect, which can deviate the skyrmions from the preferred direction. We propose a new model based on the ferromagnetic skyrmion, where the skyrmion velocity can be well controlled by adjusting the direction of the current. Using ...