Lateral-surface superlattices in systems with spin-orbit coupling: Quantum states and bloch oscillations in an electric field

2008 ◽  
Vol 2 (4) ◽  
pp. 596-603
Author(s):  
V. Ya. Demikhovskii ◽  
A. A. Kayakin ◽  
E. V. Frolova
Keyword(s):  
Electric Field ◽  
Lateral Surface ◽  
Quantum States ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Bloch Oscillations

scholarly journals Layer- and gate-tunable spin-orbit coupling in a high-mobility few-layer semiconductor

2021 ◽  
Vol 7 (5) ◽  
pp. eabe2892
Author(s):  
Dmitry Shcherbakov ◽  
Petr Stepanov ◽  
Shahriar Memaran ◽  
Yaxian Wang ◽  
Yan Xin ◽  
...  
Keyword(s):  
Electric Field ◽  
High Mobility ◽  
Orbit Coupling ◽  
Spin Splitting ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Quantum Oscillations ◽  
Out Of Plane ◽  
Order Of Magnitude ◽  
Spin Degeneracy

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.

Plasmon modes in N-layer silicene structures

2021 ◽  
Author(s):  
Men Nguyen Van
Keyword(s):  
Electric Field ◽  
Random Phase ◽  
Single Layer ◽  
Plasmon Mode ◽  
Orbit Coupling ◽  
Collective Excitations ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Number Of Layers ◽  
Plasmon Modes

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.

SPIN CURRENT INDUCED ELECTRIC FIELD IN A RASHBA QUANTUM WIRE

2010 ◽  
Vol 24 (07) ◽  
pp. 649-656
Author(s):  
XI FU ◽  
GUANGHUI ZHOU
Keyword(s):  
Electric Field ◽  
Current Density ◽  
Quantum Wire ◽  
Spin Current ◽  
Scattering Matrix ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Rashba Spin

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.

scholarly journals Bloch Oscillations in Optical and Zeeman Lattices in the Presence of Spin-Orbit Coupling

2016 ◽  
Vol 117 (21) ◽  
Author(s):  
Yaroslav V. Kartashov ◽  
Vladimir V. Konotop ◽  
Dmitry A. Zezyulin ◽  
Lluis Torner
Keyword(s):  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Bloch Oscillations

scholarly journals Controllable Valley Polarization Using Silicene Double Line Defects Due to Rashba Spin-Orbit Coupling

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Hongyu Tian ◽  
ChongDan Ren ◽  
Benhu Zhou ◽  
Shaoyin Zhang ◽  
Weitao Lu ◽  
...  
Keyword(s):  
Electric Field ◽  
Parallel Line ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Double Line ◽  
Transmission Coefficients ◽  
Rashba Spin ◽  
Valley Polarization ◽  
Line Defects

AbstractWe theoretically investigate the valley polarization in silicene with two parallel line defects due to Rashba spin-orbit coupling (RSOC). It is found that as long as RSOC exceeds the intrinsic spin-orbit coupling (SOC), the transmission coefficients of the two valleys oscillate with the same periodicity and intensity, which consists of wide transmission peaks and zero-transmission plateaus. However, in the presence of a perpendicular electric field, the oscillation periodicity of the first valley increases, whereas that of the second valley shortens, generating the corresponding wide peak-zero plateau regions, where perfect valley polarization can be achieved. Moreover, the valley polarizability can be changed from 1 to −1 by controlling the strength of the electric field. Our findings establish a different route for generating valley-polarized current by purely electrical means and open the door for interesting applications of semiconductor valleytronics.

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