The Bound-state Soliton Solutions of a Higher-order Nonlinear Schrödinger Equation for Inhomogeneous Heisenberg Ferromagnetic System

By studying an appropriate Riemann-Hilbert (RH) problem, the inverse scattering of a higher-order nonlinear Schrödinger equation for inhomogeneous Heisenberg ferromagnetic system with zero boundary condition is calculated. The RH problem of reflection coefficient with multiple high-order poles is obtained. Meanwhile, the calculation formulas of bound state (BS) solitons and multiple BS solitons corresponding to one high-order pole and multiple high-order poles are also calculated respectively. Finally, the corresponding soliton solution model is calculated according to the corresponding formula. Simultaneously, we also obtain the interaction between BS soliton and multiple BS solitons, and between multiple BS solitons and multiple BS solitons.

FLUXGATE MAGNETOMETERS WITH A NEW EXCITATION METHOD BASED ON MAGNETOELECTRIC INTERACTION

The analysis of the functional peculiarities of the known flux gates has shown that the constructive and technological methods used to increase their operational characteristics within the framework of traditional so-lutions have basically exhausted themselves. The paper proposes a method for exciting flux gates based on a new physical principle relying on the effect of magnetoelectric interaction. The possibility of obtaining a magnetoelectric effect in local inhomogeneities of solid-state structures of ferrite elements of flux-gates when exposed to an alternating electric field is analyzed and substantiated. In this case, in the entire volume of the fer-romagnetic core at the same frequencies of electromechanical and magnetic resonances, a modulating physical process is excited in the form of a standing magnetoelectric wave. This creates a corresponding magnetic modu-lation structure in the entire volume of the ferromagnetic system of the flux gate. The considered design of a fluxgate modulator implements a new method of exciting flux gates, containing a ferromagnetic rod system in the form of two ferrite rod half-elements, located coaxially and joined together by a ferrite permanent magnet with magnetization along the axis of the rods. The authors have experimentally studies a new method for exci¬ting flux gates. The proposed method for exciting flux gates opens up wide opportunities for research in a new direction in science – spintronics, in particular, the applied use of magnetoelectric interaction, which can be effectively used to create various options for flux gates based on new physical principles of operation.

On the invariant analysis, symmetry reduction with group-invariant solution and the conservation laws for (2 + 1)-dimensional modified Heisenberg ferromagnetic system

In this paper, a [Formula: see text]-dimensional modified Heisenberg ferromagnetic system, which appears in the biological pattern formation and in the motion of magnetization vector of the isotropic ferromagnet, is being investigated with the aim of exploring its similarity solutions. With the aid of Lie symmetry analysis, this system of partial differential equations has been reduced to a new system of ordinary differential equations, which brings an analytical solution of the main system. Infinitesimal generators, commutator table, and the group-invariant solutions have been carried out by using Lie symmetry approach. Moreover, conservation laws of the above mentioned system have been obtained by utilizing the new conservation theorem proposed by Ibragimov. By applying this analysis, the obtained results might be helpful to understand the physical structure of this model and show the authenticity and effectiveness of the proposed method.

Multiple superconducting phases in a nearly ferromagnetic system

The nearly ferromagnetic superconductor UTe2 shows several intriguing phenomena, including an extraordinary reinforcement of superconductivity in very strong magnetic fields. Here we show that pressure tunes the system to a more correlated state and probable magnetic order. The superconducting critical temperature is also strongly enhanced, reaching almost 3 K, a new record for U-based heavy fermion superconductors. Most spectacularly under pressure we find a transition within the superconducting state, putting UTe2 among the very rare systems having multiple superconducting phases. UTe2 under pressure is a treasure trove of several of the most fascinating phenomena in unconventional superconductivity and may well be a keystone in their understanding.

Study of Phenomenon STT (Spin Transfer Torque) on Permalloy NiFe Material Shaped Nanowire Using Micromagnetic Simulation

STT is a process of controlling the spin currents in spintronic. This simulation aims to know the properties of NiFe permalloy materials' properties by studying STT phenomenon-shaped nanowire that can be applied in storage devices, like MRAM. The material's magnetic properties include magnetization value, energy in the ferromagnetic system, and the speed of the domain wall movement, obtained by injecting the electric current density through a micromagnetic simulation using the NMAG program. This simulation's result is that the domain wall's position will shift faster along the nanowire when we inject current density to the nanowire. Current density injection will produce a domain wall pressure on the domain structure, resulting in a change in the material's magnetization value. The graph of magnetization relation to time (M-t), shown along with the increasing electric current density, we obtain oscillation magnetization change will increase. The larger the given diameter, the total energy generated will increase, demagnetization energy tends to be greater than the energy exchange. The greater the polarization of the material provided at the same diameter, the speed of the domain wall movement will be greater too.