Koley Arpita, Maiti Santanu K, Pérez Laura M, Silva Judith Helena Ojeda, Laroze David
Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700 108, India.
Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica 1000000, Chile.
Micromachines (Basel). 2021 Aug 27;12(9):1021. doi: 10.3390/mi12091021.
In this work, we perform a numerical study of magnetoresistance in a one-dimensional quantum heterostructure, where the change in electrical resistance is measured between parallel and antiparallel configurations of magnetic layers. This layered structure also incorporates a non-magnetic spacer, subjected to quasi-periodic potentials, which is centrally clamped between two ferromagnetic layers. The efficiency of the magnetoresistance is further tuned by injecting unpolarized light on top of the two sided magnetic layers. Modulating the characteristic properties of different layers, the value of magnetoresistance can be enhanced significantly. The site energies of the spacer is modified through the well-known Aubry-André and Harper (AAH) potential, and the hopping parameter of magnetic layers is renormalized due to light irradiation. We describe the Hamiltonian of the layered structure within a tight-binding (TB) framework and investigate the transport properties through this nanojunction following Green's function formalism. The Floquet-Bloch (FB) anstaz within the minimal coupling scheme is introduced to incorporate the effect of light irradiation in TB Hamiltonian. Several interesting features of magnetotransport properties are represented considering the interplay between cosine modulated site energies of the central region and the hopping integral of the magnetic regions that are subjected to light irradiation. Finally, the effect of temperature on magnetoresistance is also investigated to make the model more realistic and suitable for device designing. Our analysis is purely a numerical one, and it leads to some fundamental prescriptions of obtaining enhanced magnetoresistance in multilayered systems.
在这项工作中，我们对一维量子异质结构中的磁电阻进行了数值研究，其中在磁性层的平行和反平行配置之间测量电阻变化。这种层状结构还包含一个受准周期势作用的非磁性间隔层，该间隔层被中心夹在两个铁磁层之间。通过在两侧磁性层顶部注入非偏振光，可进一步调节磁电阻的效率。通过调制不同层的特性，可以显著提高磁电阻的值。间隔层的位点能量通过著名的奥布里 - 安德烈和哈珀（AAH）势进行修改，并且由于光照射，磁性层的跳跃参数被重整化。我们在紧束缚（TB）框架内描述层状结构的哈密顿量，并根据格林函数形式研究通过该纳米结的输运性质。在最小耦合方案中引入弗洛凯 - 布洛赫（FB）假设，以将光照射的影响纳入TB哈密顿量。考虑到中心区域的余弦调制位点能量与受光照射的磁性区域的跳跃积分之间的相互作用，呈现了磁输运性质的几个有趣特征。最后，还研究了温度对磁电阻的影响，以使模型更现实并适用于器件设计。我们的分析纯粹是数值分析，它得出了在多层系统中获得增强磁电阻的一些基本准则。
