Gate-controlled proximity magnetoresistance in In1-xGaxAs/(Ga,Fe)Sb bilayer heterostructures
Gate-controlled proximity magnetoresistance in In1-xGaxAs/(Ga,Fe)Sb bilayer heterostructures
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In1-xGaxAs/(Ga,Fe)Sb 双层异质结构中的栅控邻近磁阻
DOI：
10.1103/physrevb.105.235202
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发表时间：
2022
影响因子：
3.7
通讯作者：
Tanaka Masaaki
中科院分区：
文献类型：
--
作者：
Takiguchi Kosuke;Okamura Kyosuke;Anh Le Duc;Tanaka Masaaki
磁邻近效应（MPE），即磁性不同层界面处的铁磁（FM）耦合，作为将铁磁性引入高迁移率非磁性（NM）导电通道的有前景的途径而引起了广泛关注。最近，我们课题组在NM半导体InAs量子阱(QW)层和FM半导体(Ga,Fe)Sb层之间的界面处发现了由MPE引起的巨邻近磁阻(PMR)。 NM半导体中的MPE可以通过施加栅极电压并控制InAs QW中的电子波函数渗透到邻近的绝缘FM(Ga,Fe)Sb层中来调制。然而，在 InAs/(Ga,Fe)Sb 界面获得强 MPE 的最佳条件尚未明确。在本文中，我们系统地研究了(、5、7.5和10%)/(Ga,Fe)Sb双层半导体异质结构在宽范围栅极电压下的PMR特性。 Ga 的加入改变了 InAs 薄膜的电子结构，从而改变了电子载流子的有效质量和 QW 电势。我们对这些(Ga,Fe)Sb异质结构中PMR的实验结果和理论分析表明，MPE不仅取决于电子波函数对(Ga,Fe)Sb的渗透程度，还取决于电子密度。这些发现有助于我们揭示基于半导体的 NM/FM 异质结中 MPE 的微观机制。
The magnetic proximity effect (MPE), ferromagnetic (FM) coupling at the interface of magnetically dissimilar layers, has attracted much attention as a promising pathway for introducing ferromagnetism into a high-mobility nonmagnetic (NM) conducting channel. Recently, our group found giant proximity magnetoresistance (PMR), which is caused by MPE at an interface between a NM semiconductor InAs quantum well (QW) layer and a FM semiconductor (Ga,Fe)Sb layer. The MPE in the NM semiconductor can be modulated by applying a gate voltage and controlling the penetration of the electron wave function in the InAs QW into the neighboring insulating FM (Ga,Fe)Sb layer. However, optimal conditions to obtain strong MPE at the InAs/(Ga,Fe)Sb interface have not been clarified. In this paper, we systematically investigate the PMR properties of(, 5, 7.5, and 10%)/(Ga,Fe)Sb bilayer semiconductor heterostructures under a wide range of gate voltage. The inclusion of Ga alters the electronic structures of the InAs thin film, changing the effective mass and the QW potential of electron carriers. Our experimental results and theoretical analysis of the PMR in these(Ga,Fe)Sb heterostructures show that the MPE depends not only on the degree of penetration of the electron wave function into (Ga,Fe)Sb but also on the electron density. These findings help us to unveil the microscopic mechanism of MPE in semiconductor-based NM/FM heterojunctions.