Spin contribution to the instability of THz plasma waves

Abstract

When the boundary conditions of the source and drain are asymmetric, the plasma waves may become unstable in the channel of a field effect transistor (FET). We use the quantum magnetohydrodynamic model to study the influence of the quantum Bohm potential, Fermi statistical pressure, and electron spin effects on the stability of THz plasma waves propagating perpendicular to the magnetic field in the FET. A dispersion equation governing the THz plasma oscillation is obtained. Numerical results have shown that the presence of spin effects has enlarged the instable range of β, enhanced the instability increment, and made the frequency of THz plasma waves larger. The research shows that nanometer FETs with spin effects have advantages in realizing practical terahertz radiation.

Effect of spin on the instability of THz plasma waves in field-effect transistors under non-ideal boundary conditions

“…The results show that the size of h has a very small effect on the oscillation frequency and the instability. Compared with the results in [30], the oscillation frequency and instability gain of THz plasma wave increase with increasing .…”

“…Meanwhile, the quantum effect and spin effect enhance the emission of THz waves, and the boundary conditions can affect the oscillation frequency and the instability gain of plasma THz waves. In [30], the effects of spin, quantum effects, drift velocity and other factors on the oscillation frequency and instability gain of THz plasma waves are investigated under asymmetric boundary conditions. Compared with the results in [30], we found that the influence of boundary conditions is very important.…”

“…In [30], the effects of spin, quantum effects, drift velocity and other factors on the oscillation frequency and instability gain of THz plasma waves are investigated under asymmetric boundary conditions. Compared with the results in [30], we found that the influence of boundary conditions is very important. The oscillation frequency with asymmetric boundary conditions is smaller than that under non-ideal boundary conditions, but the instability gain of THz plasma waves becomes lower under non-ideal boundary conditions.…”

Magnetorotational instability in dense electron–positron–ion plasmas

“…Safdar et al 31 investigated magnetosonic waves in the presence of degenerate pressure due to Landau diamagnetic levels and Pauli spin magnetization and explored a new propagation mode. A model for dense degenerate plasmas that incorporates electron spin 32 , magnetosonic solitary waves 33 , effects of the spin on the EM wave modes in magnetized plasmas 34 , basic properties of magnetosonic waves in a magnetorotating spin quantum plasma 35 and instability of Terahertz (THz) plasma waves 36 in quantum field effect transistors (FETs) with the spin effects are extensively studied and were found to play major roles in specifying the nature, structures and features of astrophysical (neutron stars and white dwarfs) and laboratory (semiconductor) plasmas.…”