Properties of a5T2 in iron(II) under the action of arbitrary-symmetry ligand fields and spin-orbit coupling: II. On the electric field gradient and susceptibility tensor

1975 ◽  
Vol 68 (1) ◽  
pp. 181-191 ◽  
Author(s):  
R. Zimmermann
1985 ◽  
Vol 63 (12) ◽  
pp. 1540-1547 ◽  
Author(s):  
D. G. Rancourt ◽  
J. M. Daniels ◽  
H-Y. Lam

The 57Fe Mössbauer spectrum of Fe2As has been measured in the temperature range 25–456 K. Evidence is found for two factors that affect the spectrum and that had been neglected in earlier investigations. These are (i) spin relaxation in a time period that is short compared with the characteristic Mössbauer measurement time and (ii) an anisotropy induced in the electric field gradient at the 57Fe nuclei, by the Weiss molecular field, via the spin orbit coupling. Taking these factors into account, we find that the Mössbauer spectra give consistent and physically reasonable parameters over the whole temperature range. There is also agreement with previous neutron-diffraction studies in that the spins in the antiferromagnetic phase are perpendicular to the c axis. The disagreements reported in earlier studies are seen to arise from a neglect of these factors.


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.


Author(s):  
Men Nguyen Van

Abstract We investigate the plasmon properties in N-layer silicene systems consisting of N, up to 6, parallel single-layer silicene under the application of an out-of-plane electric field, taking into account the spin-orbit coupling within the random-phase approximation. Numerical calculations demonstrate that N undamped plasmon modes, including one in-phase optical and (N-1) out-of-phase acoustic modes, continue mainly outside the single-particle excitation area of the system. As the number of layers increases, the frequencies of plasmonic collective excitations increase and can become much larger than that in single layer silicene, more significant for high-frequency modes. The optical (acoustic) plasmon mode(s) noticeably (slightly) decreases with the increase in the bandgap and weakly depends on the number of layers. We observe that the phase transition of the system weakly affects the plasmon properties, and as the bandgap caused by the spin-orbit coupling equal that caused by the external electric field, the plasmonic collective excitations and their broadening function in multilayer silicene behave similarly to those in multilayer gapless graphene structures. Our investigations show that plasmon curves in the system move toward that in single layer silicene as the separation increases, and the impacts of this factor can be raised by a large number of layers in the system. Finally, we find that the imbalanced carrier density between silicene layers significantly decreases plasmon frequencies, depending on the number of layers.


2010 ◽  
Vol 24 (07) ◽  
pp. 649-656
Author(s):  
XI FU ◽  
GUANGHUI ZHOU

We investigate theoretically the spin current and spin current induced electric field in a weak Rashba spin-orbit coupling quantum wire (QW) using a definition for spin current by means of scattering matrix. It is found that there exists two non-zero linear spin current density elements which have oscillation peaks at the center of QW and their strengths can be changed by the number of propagation modes and Rashba constant, respectively. Moreover, the spin current induced electric field has also been calculated and its strength is measurable with present technology with which can be used to detect spin current.


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