Modulational instability, quantum breathers and two-breathers in a frustrated ferromagnetic spin lattice under an external magnetic field

2018 ◽  
Vol 27 (9) ◽  
pp. 097501 ◽  
Author(s):  
Wanhan Su ◽  
Jiayu Xie ◽  
Tianle Wu ◽  
Bing Tang
1989 ◽  
Vol 41 (2) ◽  
pp. 289-300 ◽  
Author(s):  
V. I. Karpman ◽  
A. G. Shagalov

The modulational instability of a whistler wave propagating along an external magnetic field is investigated, taking into account the dispersion of the low-frequency modulations. The dispersive effects are significant if the modulation frequencies Ω are comparable to or greater than the ion cyclotron frequency ωci. It is shown that in this case there are four unstable branches: the long-wave modulational instability and three others with much larger growth rates. At Ω≪ωci the latter correspond to fast magnetic sound, Alfvén and slow magnetic sound branches.


1974 ◽  
Vol 33 (16) ◽  
pp. 937-940 ◽  
Author(s):  
Clyde A. Hutchison ◽  
Marvin D. Kemple ◽  
Yung-Tsai Yen

2000 ◽  
Vol 62 (5) ◽  
pp. 3372-3380 ◽  
Author(s):  
H.-D. Pfannes ◽  
A. Mijovilovich ◽  
R. Magalhães-Paniago ◽  
R. Paniago

Galaxies ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 48
Author(s):  
Wael F. El-Taibany ◽  
Nabila A. El-Bedwehy ◽  
Nora A. El-Shafeay ◽  
Salah K. El-Labany

The modulational instability of ion-acoustic waves (IAWs) in a four-component magneto-plasma system consisting of positive–negative ions fluids and non-Maxwellian (r,q) distributed electrons and positrons, is investigated. The basic system of fluid equations is reduced to a three-dimensional (3D) nonlinear Schrödinger Equation (NLS). The domains of the IAWs stability are determined and are found to be strongly affected by electrons and positrons spectral parameters r and q and temperature ratio Tp/Te (Tp and Te are positrons and electrons temperatures, respectively). The existence domains, where we can observe the ion-acoustic rogue waves (IARWs) are determined. The basic features of IARWs are analyzed numerically against the distribution parameters and the other system physical parameters as Tp/Te and the external magnetic field strength. Moreover, a comparison between the first- and second-order rogue waves solution is presented. Our results show that the nonlinearity of the system increases by increasing the values of the non-Maxwellian parameters and the physical parameters of the system. This means that the system gains more energy by increasing r, q, Tp, and the external magnetic field through the cyclotron frequency ωci. Finally, our theoretical model displays the effect of the non-Maxwellian particles on the MI of the IAWs and RWs and its importance in D–F regions of Earth’s ionosphere through (H+,O2−) and (H+,H−) electronegative plasmas.


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