Spin-Induced Localized Density Excitations in Quantum Plasmas

In this paper, the dominant role of electron inertia on the dynamics of localized density excitations is studied in a quantum plasma in the presence of electron spin effects. Using the quantum magnetohydrodynamics model including electron tunneling and spin polarization phenomena, it is revealed that quantum effects such as plasma paramagnetism and diamagnetism play inevitable role in soliton existence criteria in quantum plasmas. Furthermore, it is shown that the magnetosonic localized density-excitation stability depends strongly on the quantum system dimensionality. Two distinct regions of soliton stability are shown to exist depending on the value of the electron effective mass, where the soliton amplitude variation with respect to the external magnetic field strength is quite opposite in these regions. Current findings can be important in the study of dynamical nonlinear wave features in dense astrophysical or inertial-confined plasmas.