scholarly journals Magnetic competition in topological kagome magnets

2021 ◽  
Author(s):  
Thanh-Mai Thi Tran ◽  
Duong-Bo Nguyen ◽  
Hong-Son Nguyen ◽  
Minh-Tien Tran
Keyword(s):  
Variational Principle ◽  
Spin Exchange ◽  
Tight Binding ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Zero Temperature ◽  
Electron Dynamics ◽  
Hall Conductance ◽  
Magnetic Phases ◽  
Out Of Plane

Abstract Magnetic competition in topological kagome magnets is studied by incorporating the spin-orbit coupling, anisotropic Hund coupling and spin exchange into a tight-binding electron dynamics in the kagome lattice. Using the Bogoliubov variational principle we find the stable phases at zero and finite temperatures. At zero temperature and in the strong Ising-Hund coupling regime, a magnetic tunability from the out-of-plane ferromagnetism to the in-plane antiferromagnetism is achieved through a universal property of the critical in-plane Hund coupling. At low temperature the out-of-plane ferromagnetism is stable until a finite crossing temperature. Above the crossing temperature the in-plane antiferromagnetism is stable, but the magnetization of the out-of-plane ferromagnetism still survives. This suggests a metastable coexistence of these magnetic phases in a finite temperature range. A large anomalous Hall conductance is observed in the Ising-Hund coupling limit.

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.

scholarly journals Tight-binding theory of the spin-orbit coupling in graphene

2010 ◽  
Vol 82 (24) ◽  
Author(s):  
Sergej Konschuh ◽  
Martin Gmitra ◽  
Jaroslav Fabian
Keyword(s):  
Tight Binding ◽  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Binding Theory

scholarly journals Topological and magnetic phases with strong spin-orbit coupling on the hyperhoneycomb lattice

2014 ◽  
Vol 89 (20) ◽  
Author(s):  
Eric Kin-Ho Lee ◽  
Subhro Bhattacharjee ◽  
Kyusung Hwang ◽  
Heung-Sik Kim ◽  
Hosub Jin ◽  
...  
Keyword(s):  
Orbit Coupling ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Magnetic Phases ◽  
Strong Spin

scholarly journals Intrinsic Spin-Orbit Coupling in Zigzag and Armchair Graphene Nanoribbons

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Ying Li ◽  
Erhu Zhang ◽  
Baihua Gong ◽  
Shengli Zhang
Keyword(s):  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Geometrical Parameters ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Binding Model ◽  
Tight Binding Approximation ◽  
Energy Gaps ◽  
Armchair Graphene Nanoribbons ◽  
Armchair Graphene

Starting from a tight-binding model, we derive the energy gaps induced by intrinsic spin-orbit (ISO) coupling in the low-energy band structures of graphene nanoribbons. The armchair graphene nanoribbons may be either semiconducting or metallic, depending on their widths in the absence of ISO interactions. For the metallic ones, the gaps induced by ISO coupling decrease with increasing ribbon widths. For the ISO interactions, we find that zigzag graphene nanoribbons with odd chains still have no band gaps while those with even chains have gaps with a monotonic decreasing dependence on the widths. First-principles calculations have also been carried out, verifying the results of the tight-binding approximation. Our paper reveals that the ISO interaction of graphene nanoribbons is governed by their geometrical parameters.

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