Research Article
Magnetic Properties of One-dimensional Helical Spin System with Isotropic Spin Exchanges Under the Effect of DM and KSEA
Issue:
Volume 15, Issue 2, April 2026
Pages:
13-23
Received:
28 January 2026
Accepted:
12 February 2026
Published:
5 March 2026
Abstract: In the present work, we report on a theoretical investigation of the magnetoelectric parameters of the helical Heisenberg multiferroic spin chain model. The spin-wave approximation in the bosonization process is used to evaluate the energy spectrum of the quadratic form of the model as that of regular quantum gases. The quantized form of the model is conveniently treated using the canonical ensemble in terms of the free energy developed by the use of Landau theory. Following the Fermi-Dirac statistics of quantum gases, the joint effect of Dzyaloshinskii -Mriya (DM) and Kaplan-Shekhtman-Entin-Wohlman-Aharony (KSEA) interactions on the magnetoelectric properties of the helical multiferroic spin structure controlled by a static electric field in the y-direction and a magnetic field in the z-direction is quantified. The magnetization, susceptibility, and electric polarization are used as measurable parameters. The work convincingly establishes that the juxtaposition of KSEA interactions to DM interactions is worthy since, on the one hand, it amplifies the magnetic property of the system, and on the other hand makes it possible to control the phase transition dynamics induced in such materials by the symmetric inversion due to the DM interactions. At low temperature, the measurable parameters are closely related to ferroelectricity and ferromagnetism in multiferroic materials, where all effects favor the symmetrization mechanism and hence magnetoelectric properties. These properties are critical in spintronics and information storage control.
Abstract: In the present work, we report on a theoretical investigation of the magnetoelectric parameters of the helical Heisenberg multiferroic spin chain model. The spin-wave approximation in the bosonization process is used to evaluate the energy spectrum of the quadratic form of the model as that of regular quantum gases. The quantized form of the model ...
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Research Article
Influence of Jovian Planetary Motion on Sunspot Cycles
Fred John Cadieu*
Issue:
Volume 15, Issue 2, April 2026
Pages:
24-29
Received:
13 February 2026
Accepted:
28 February 2026
Published:
12 March 2026
DOI:
10.11648/j.ajmp.20261502.12
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Abstract: Sunspots are observable phenomena that emerge on the Sun’s surface, typically appearing in groups during intervals when the toroidal magnetic field of the Sun is heightened. These occurrences are not solely determined by the magnetic field’s strength; there is also a stochastic, or noise-related, component that influences sunspot manifestation during these elevated periods. This paper demonstrates that the periods of increased toroidal magnetic field are driven by the collective movement of the Jovian planets, which alters the location of the solar system’s center of mass relative to the Sun’s center. This dynamic motion introduces a cycle that is very close to 11 years in length. When both polarities of the Sun’s magnetic field are considered, this results in an overall 22-year magnetic cycle. For these effects to be effective the Sun’s dynamo must extend into the near surface layers. Sunspots emerge over both the northern and southern hemispheres of the Sun, following the typical butterfly pattern that is characteristic of sunspot distribution. While the collective motion of the Jovian planets drives the cyclical maxima in the Sun’s toroidal magnetic field, it is identified as a necessary-but not solely sufficient-factor for the development of sunspots. Based on the influence of the Jovian planets, it is predicted that the maximum for solar cycle 25 will occur between November and December 2024. Furthermore, solar cycle 26 is expected to reach its maximum around January 2037.
Abstract: Sunspots are observable phenomena that emerge on the Sun’s surface, typically appearing in groups during intervals when the toroidal magnetic field of the Sun is heightened. These occurrences are not solely determined by the magnetic field’s strength; there is also a stochastic, or noise-related, component that influences sunspot manifestation duri...
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