Spin-Orbit Coupling and Zero-Field Electron Spin Splitting in AlGaN/AlN/GaN Heterostructures with a Polarization Induced Two-Dimensional Electron Gas

2006 ◽  
Vol 955 ◽  
Author(s):  
Ç. Kurdak ◽  
N. Biyikli ◽  
H. Cheng ◽  
U. Ozgur ◽  
H. Morkoç ◽  
...  

ABSTRACTWe studied spin-orbit coupling in wurtzite AlxGa1−xN/AlN/GaN heterostructures with different Al concentrations using weak antilocalization measurements at 1.6 K. Using the persistent photoconductivity effect we change the carrier density in controllable manner. We find that the electron spin splitting energies does not scale linearly with the Fermi wavevector at high carrier densities. From this deviation, for the first time, we are able to extract the cubic spin-orbit parameter for this material system.

2021 ◽  
Vol 7 (5) ◽  
pp. eabe2892
Author(s):  
Dmitry Shcherbakov ◽  
Petr Stepanov ◽  
Shahriar Memaran ◽  
Yaxian Wang ◽  
Yan Xin ◽  
...  

Spin-orbit coupling (SOC) is a relativistic effect, where an electron moving in an electric field experiences an effective magnetic field in its rest frame. In crystals without inversion symmetry, it lifts the spin degeneracy and leads to many magnetic, spintronic, and topological phenomena and applications. In bulk materials, SOC strength is a constant. Here, we demonstrate SOC and intrinsic spin splitting in atomically thin InSe, which can be modified over a broad range. From quantum oscillations, we establish that the SOC parameter α is thickness dependent; it can be continuously modulated by an out-of-plane electric field, achieving intrinsic spin splitting tunable between 0 and 20 meV. Unexpectedly, α could be enhanced by an order of magnitude in some devices, suggesting that SOC can be further manipulated. Our work highlights the extraordinary tunability of SOC in 2D materials, which can be harnessed for in operando spintronic and topological devices and applications.


2018 ◽  
Vol 97 (8) ◽  
Author(s):  
Jianhong Dai ◽  
Yunyu Yin ◽  
Xiao Wang ◽  
Xudong Shen ◽  
Zhehong Liu ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
I. N. Yakovkin

The electronic structure of Au(111) films is studied by means of relativistic DFT calculations. It is found that the twinning of the surface bands, observed in photoemission experiment, does not necessarily correspond to the spin-splitting of the surface states caused by the break of the inversion symmetry at the surface. The twinning of the bands of clean Au(111) films can be obtained within nonrelativistic or scalar-relativistic approximation, so that it is not a result of spin-orbit coupling. However, the spin-orbit coupling does not lead to the spin-splitting of the surface bands. This result is explained by Kramers’ degeneracy, which means that the existence of a surface itself does not destroy the inversion symmetry of the system. The inversion symmetry of the Au(111) film can be broken, for example, by means of adsorption, and a hydrogen monolayer deposited on one face of the film indeed leads to the appearance of the spin-splitting of the bands.


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