Yang Chanuk, Lee Jae-Hyun, Jo Myunglae, Choi Hyung Kook, Park Seondo, Kim Young Duck, Cho Sung Un, Kim Donguk, Park Yun Daniel
Department of Physics & Astronomy and Institute of Applied Physics, Seoul National University, Seoul, 08826, Korea.
Component Solution Business Unit, Samsung Electro-Mechanics, Suwon, 16674, Korea.
Sci Rep. 2019 Sep 20;9(1):13633. doi: 10.1038/s41598-019-50115-1.
Strain perturbs atomic ordering in solids, with far-reaching consequences from an increased carrier mobility to localization in Si, stabilization of electric dipoles and nanomechanical transistor action in oxides, to the manipulation of spins without applying magnetic fields in n-GaAs. In GaMnAs, a carrier-mediated ferromagnetic semiconductor, relativistic spin-orbit interactions - highly strain-dependent magnetic interactions - play a crucial role in determining the magnetic anisotropy (MA) and anisotropic magnetoresistance (AMR). Strain modifies the MA and AMR in a nanomachined GaMnAs structure as measured by the anomalous Hall effect (AHE) and the planar Hall effect (PHE). Here, we report an MA modification by strain relaxation in an isolated GaMnAs Hall bar structure and by applying a range of local strains via fabricating asymmetrically mechanically buckled GaMnAs micro-Hall bar structures. In the AHE and PHE measurements, we observe a reduction in the in-plane MA and an enhancement in the out-of-plane MA as the compressive strain due to the lattice mismatch relaxes in the suspended structure. The functionality of such mechanical manipulation, as well as the two-level mechanical state and the corresponding AHE responses, is demonstrated by a fully scalable binary mechanical memory element in a GaMnAs single Hall cross structure.
应变会扰乱固体中的原子有序排列，其影响深远，从硅中载流子迁移率的增加到载流子的局域化，从氧化物中电偶极子的稳定和纳米机械晶体管效应，到在n型砷化镓中无需施加磁场就能操控自旋。在载流子介导的铁磁半导体砷化镓锰中，相对论性自旋轨道相互作用——高度依赖应变的磁相互作用——在决定磁各向异性（MA）和各向异性磁阻（AMR）方面起着关键作用。通过反常霍尔效应（AHE）和平面霍尔效应（PHE）测量发现，应变会改变纳米加工的砷化镓锰结构中的MA和AMR。在此，我们报告了在孤立的砷化镓锰霍尔条形结构中通过应变弛豫以及通过制造不对称机械弯曲的砷化镓锰微霍尔条形结构施加一系列局部应变来实现MA的改变。在AHE和PHE测量中，我们观察到随着悬浮结构中由于晶格失配产生的压缩应变弛豫，面内MA减小，面外MA增大。在砷化镓锰单霍尔交叉结构中，一个完全可扩展的二进制机械存储元件展示了这种机械操控的功能，以及两级机械状态和相应的AHE响应。
