Zhu Rui, Gao Zhibin, Liang Qijie, Hu Junxiong, Wang Jian-Sheng, Qiu Cheng-Wei, Wee Andrew Thye Shen
Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore.
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
ACS Appl Mater Interfaces. 2021 Aug 11;13(31):37527-37534. doi: 10.1021/acsami.1c10500. Epub 2021 Aug 1.
Anisotropy in crystals usually has remarkable consequences in two-dimensional (2D) materials, for example, black phosphorus, PdSe, and SnS, arising from different lattice periodicities along different crystallographic directions. Electrical anisotropy has been successfully demonstrated in 2D materials, but anisotropic magnetoresistance in 2D materials is rarely studied. Herein, we report anisotropic magnetoresistance in layered nonmagnetic semiconducting PdSe flakes. Anisotropic magnetoresistance along the two crystalline axes under a perpendicular magnetic field is demonstrated, and the magnetoresistance along the -axis is apparently different from the magnetoresistance along the -axis. The magnetoresistance can also be flexibly tuned by applying a gate voltage, leveraging the semiconductor properties of PdSe. The computed anisotropic electronic density of states and electronic mobility with ab initio density functional calculations support the anisotropic and measured magnetoresistance. Our findings advance the understanding of magnetoresistance in anisotropic transition-metal dichalcogenides and pave the way for potential applications in anisotropic spintronic devices.
晶体中的各向异性在二维（2D）材料中通常会产生显著影响，例如黑磷、PdSe和SnS，这是由于沿不同晶体学方向的晶格周期性不同所致。二维材料中的电各向异性已得到成功证明，但二维材料中的各向异性磁阻很少被研究。在此，我们报道了层状非磁性半导体PdSe薄片中的各向异性磁阻。展示了在垂直磁场下沿两个晶轴的各向异性磁阻，并且沿x轴的磁阻明显不同于沿y轴的磁阻。通过施加栅极电压，利用PdSe的半导体特性，磁阻也可以灵活调节。用从头算密度泛函计算得出的各向异性电子态密度和电子迁移率支持了各向异性以及测量得到的磁阻。我们的发现增进了对各向异性过渡金属二硫属化物中磁阻的理解，并为各向异性自旋电子器件的潜在应用铺平了道路。
