Superparamagnetism, magnetoresistance and anomalous Hall effect in amorphous Mn x Si 1 − x semiconductor films

2015 ◽  
Vol 623 ◽  
pp. 438-441 ◽  
Author(s):  
Ai-chun Yang ◽  
Kun Zhang ◽  
Shi-shen Yan ◽  
Shi-shou Kang ◽  
Yu-feng Qin ◽  
...  
2019 ◽  
Vol 33 (13) ◽  
pp. 1950121 ◽  
Author(s):  
Juan Pei ◽  
Shu-Qin Xiao ◽  
Li-Min He ◽  
Kun Zhang ◽  
Huan-Huan Li ◽  
...  

The large nonlinear Hall effect was found in (FeCo)[Formula: see text]Ge[Formula: see text]/Ge heterojunctions formed by sputtering amorphous [Formula: see text]-type (FeCo)[Formula: see text]Ge[Formula: see text] magnetic semiconductor films on near intrinsic n-type Ge substrate. It is very interesting that the mechanisms of the large nonlinear Hall effect in (FeCo)[Formula: see text]Ge[Formula: see text]/Ge heterojunctions are different at different temperature ranges. Below 10 K, the Hall resistance of (FeCo)[Formula: see text]Ge[Formula: see text]/Ge heterojunctions is almost the same as the anomalous Hall effect of (FeCo)[Formula: see text]Ge[Formula: see text] ferromagnetic films. While the temperature increased from 10 to 60 K, the nonlinear Hall resistance, longitudinal conductance, and magnetoresistance all increased quickly and reached the maximum at T[Formula: see text]=[Formula: see text]60 K. In this case, thermally excited conducting carriers can tunnel through the interfacial potential barrier in (FeCo)[Formula: see text]Ge[Formula: see text]/Ge heterojunctions. Thus, in the range of 10–60 K, the enhanced nonlinear Hall resistance can be attributed to the anomalous Hall effect which was further enhanced by interfacial Rashba spin–orbit coupling effect. When the temperature further increased from 60 to 250 K, the interfacial potential barrier weakened gradually, and the Hall resistance and magnetoresistance decreased due to the shunting of the Ge substrate. In this case, the nonlinear Hall effect of (FeCo)[Formula: see text]Ge[Formula: see text]/Ge heterojunctions can be explained very well by the two-band model of nonlinear Hall effect.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fei Wang ◽  
Xuepeng Wang ◽  
Yi-Fan Zhao ◽  
Di Xiao ◽  
Ling-Jie Zhou ◽  
...  

AbstractThe Berry phase picture provides important insights into the electronic properties of condensed matter systems. The intrinsic anomalous Hall (AH) effect can be understood as the consequence of non-zero Berry curvature in momentum space. Here, we fabricate TI/magnetic TI heterostructures and find that the sign of the AH effect in the magnetic TI layer can be changed from being positive to negative with increasing the thickness of the top TI layer. Our first-principles calculations show that the built-in electric fields at the TI/magnetic TI interface influence the band structure of the magnetic TI layer, and thus lead to a reconstruction of the Berry curvature in the heterostructure samples. Based on the interface-induced AH effect with a negative sign in TI/V-doped TI bilayer structures, we create an artificial “topological Hall effect”-like feature in the Hall trace of the V-doped TI/TI/Cr-doped TI sandwich heterostructures. Our study provides a new route to create the Berry curvature change in magnetic topological materials that may lead to potential technological applications.


2021 ◽  
pp. 2006301
Author(s):  
Satya N. Guin ◽  
Qiunan Xu ◽  
Nitesh Kumar ◽  
Hsiang‐Hsi Kung ◽  
Sydney Dufresne ◽  
...  

2020 ◽  
Vol 4 (9) ◽  
Author(s):  
Nan Liu ◽  
Xuefan Niu ◽  
Yuxin Liu ◽  
Qinghua Zhang ◽  
Lin Gu ◽  
...  

2021 ◽  
Vol 551 ◽  
pp. 149390
Author(s):  
Weizhen Meng ◽  
Xiaoming Zhang ◽  
Weiwang Yu ◽  
Ying Liu ◽  
Lu Tian ◽  
...  

2020 ◽  
Author(s):  
Xinyang Li ◽  
Weixiao Ji ◽  
Peiji Wang ◽  
Chang-wen Zhang

Half-Dirac semimetals (HDSs), which possess 100% spin-polarizations for Dirac materials, are highly desirable for exploring various topological phases of matter, as low-dimensionality opens unprecedented opportunities for manipulating the quantum state...


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