scholarly journals Does a Spin–Orbit Coupling Between the Sun and the Jovian Planets Govern the Solar Cycle?

2008 ◽  
Vol 25 (2) ◽  
pp. 85-93 ◽  
Author(s):  
I. R. G. Wilson ◽  
B. D. Carter ◽  
I. A. Waite
Keyword(s):  
Solar Cycle ◽  
Rotation Rate ◽  
Orbital Motion ◽  
Meridional Flow ◽  
Orbit Coupling ◽  
Coupling Mechanism ◽  
The Sun ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Jovian Planets

AbstractWe present evidence to show that changes in the Sun's equatorial rotation rate are synchronized with changes in its orbital motion about the barycentre of the Solar System. We propose that this synchronization is indicative of a spin–orbit coupling mechanism operating between the Jovian planets and the Sun. However, we are unable to suggest a plausible underlying physical cause for the coupling. Some researchers have proposed that it is the period of the meridional flow in the convective zone of the Sun that controls both the duration and strength of the Solar cycle. We postulate that the overall period of the meridional flow is set by the level of disruption to the flow that is caused by changes in Sun's equatorial rotation speed. Based on our claim that changes in the Sun's equatorial rotation rate are synchronized with changes in the Sun's orbital motion about the barycentre, we propose that the mean period for the Sun's meridional flow is set by a Synodic resonance between the flow period (∼22.3 yr), the overall 178.7-yr repetition period for the solar orbital motion, and the 19.86-yr synodic period of Jupiter and Saturn.

Untersuchung zur externen Spin-Bahn-Kopplung bei aromatischen Molekülen / External Spin-Orbit-Coupling in Aromatic Molecules

1976 ◽  
Vol 31 (7) ◽  
pp. 748-753
Author(s):  
J. Friedrich ◽  
G. Weinzierl ◽  
F. Dörr
Keyword(s):  
Nuclear Charge ◽  
Heavy Atom ◽  
Orbit Coupling ◽  
Coupling Mechanism ◽  
Intermolecular Distance ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Overlap Integrals ◽  
Aromatic Molecules ◽  
Atom Effect

Abstract The influence of ethylhalogenes on the polarization of the phosphorescence of naphthalene was studied by means of the photoselection technique. It is shown that with increasing concentration and with increasing nuclear charge of the heavy atom the phosphorescence of naphthalene becomes increasingly depolarized. The influence of the external heavy atom on the Tx- and Tz- substate is stronger than on the Ty-substate. From the concentration dependence of the depolarizatign conclusions concerning the mechanism of the external spin-orbit-coupling are drawn. The dirept spin-orbit-coupling mechanism is ruled out. In the model discussed the variation of the external heavy atom effect with the intermolecular distance is related to overlap integrals.

scholarly journals Whirling interlayer fields as a new source of stable topological order in moiré CrI3

2021 ◽  
Author(s):  
Doried Ghader ◽  
Bilal Jabakhanji ◽  
Alessandro Stroppa
Keyword(s):  
Ground State ◽  
Nearest Neighbor ◽  
Current Knowledge ◽  
Orbit Coupling ◽  
Coupling Mechanism ◽  
Spin Orbit Coupling ◽  
Topological Order ◽  
Spin Orbit ◽  
Interlayer Exchange ◽  
And Control

Abstract The moiré engineering of two-dimensional magnets opens unprecedented opportunities to design novel magnetic states via the stacking-dependent magnetism. Here, we explore the formation and control of ground state topological spin structures (TSTs) in moiré CrI3 without including the nearest-neighbor (NN) Dzyaloshinskii-Moriya interactions (DMI) and dipolar interactions in the theoretical approach. Using stochastic Landau-Lifshitz-Gilbert simulations, we unveil the emergence of vortex and antivortex interlayer exchange fields at large moiré periodicity. The whirling fields stabilize spontaneous and field-assisted ground state TSTs with various topologies, including skyrmionic clusters with high topological charges. Furthermore, by examining the effect of the Kitaev interaction and the next NN DMI, we propose the latter as the unique spin-orbit coupling mechanism compatible with the experimental results on monolayer and twisted CrI3. Therefore, our study goes beyond the current knowledge about TSTs in moiré magnets, opens exciting opportunities for moiré skyrmionics, and uncovers the spin-orbit coupling in CrI3.

Studies of the Zero-Field Splitting for Mn2+ In 6H-RbMgF3 Crystal

2004 ◽  
Vol 59 (12) ◽  
pp. 961-963 ◽  
Author(s):  
Wen-Chen Zheng ◽  
Yang Mei ◽  
Xiao-Xuan Wu ◽  
Qing Zhou
Keyword(s):  
Structural Data ◽  
Orbit Coupling ◽  
Site Symmetry ◽  
Coupling Mechanism ◽  
Zero Field ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Superposition Model ◽  
Zero Field Splitting ◽  
Field Splitting

By using the spin-orbit coupling mechanism and the empirical superposition model, the zero-field splittings D of Mn2+ ions on both Mg2+ sites in hexagonal 6H-RbMgF3 crystal are calculated from the structural data of both Mg2+ sites. The calculated results of both methods confirm the suggestion that Mn2+ in 6H-RbMgF3 occupies the Mg2+ (I) site (which has D3d site symmetry) and the zero-field splitting D of 6H-RbMgF3: Mn2+ is explained reasonably.

Ab initioCI calculation of O2+predissociation phenomena induced by a spin-orbit coupling mechanism

1982 ◽  
Vol 46 (4) ◽  
pp. 779-810 ◽  
Author(s):  
Christel M. Marian ◽  
Ralf Marian ◽  
Sigrid D. Peyerimhoff ◽  
Bernd A. Hess ◽  
Robert J. Buenker ◽  
...  
Keyword(s):  
Orbit Coupling ◽  
Coupling Mechanism ◽  
Spin Orbit Coupling ◽  
Spin Orbit

The electronic spectrum of KCoF3: Exchange effects

1972 ◽  
Vol 25 (3) ◽  
pp. 453 ◽  
Author(s):  
J Ferguson ◽  
TE Wood ◽  
HJ Guggenheim
Keyword(s):  
Electronic Excitation ◽  
Exchange Interactions ◽  
Weak Field ◽  
Orbit Coupling ◽  
Coupling Mechanism ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Spectral Absorption ◽  
Exchange Effects

An analysis of the absorption spectrum of KcoF3 based on the weak field spin-orbit matrices has led to an assignment of all the doublet states of the d7 configuration using the parameters Dq = 780 cm-l, F2 = 1440cm-l, F4 = 104.5 cm-l and the spin-orbit coupling constant 5 = 490 cm-l. F2 F4, and < correspond to 91%, 94%, and 91% of their respective free ion values. The spectral absorption intensities of the spin forbidden transitions between 26000 and 40000 cm-l are much too large to be accounted for by the conventional spin-orbit coupling mechanism and one involving exchange interactions between pairs of ions is indicated. Consistent with this mechanism 1s the appearance of nine absorption regions which correspond to the simultaneous electronic excitation of pairs of ions.

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