Numerical simulation of plasma waves in a quasi-2D electron gas based on the Boltzmann transport equation

Investigation of moments-based transport models applied to plasma waves and the Dyakonov–Shur instability

“…When q | | is further increased, the limitations of the small amount of parameters in the moments-based transport models become apparent. Equation (43) has a fixed number of poles in the complex q-plane (two for the DD and DDc model, four for the HD and HDs model) which determine the behavior of m. Since this is by far not enough to completely reproduce the behavior of the BTE, which has a much higher number of poles [19,20], large deviations between the results of the simplified models and the BTE occur, and the influence of erroneous positioned poles can be seen as peeks in the mobility.…”

“…We investigate the transport models by assuming nearly constant values for all moments and the electric field, while the spatial and temporal dependency is contained in a small perturbation of the form [19,20]…”

“…With the continuity equation, the expression for the small-signal conductivity and E q i j = this can be transformed into the nonlinear scalar equation [20]…”

Investigation of the Dyakonov–Shur instability for THz wave generation based on the Boltzmann transport equation

“…The BTE yields in addition a continuum of modes [15]. In the case of a numerical solution of the BTE for each variable of the corresponding discrete system a plasma mode is obtained [16]. At small electric fields and low frequencies the two modes with the least damping are well separated from the others w.r.t.…”

“…It is easy to identify these two modes as the Vlasov modes. On the other hand, in the case of strong non-equilibrium and high frequencies identification of the two Vlasov modes by simple means is no longer possible [16]. In this case the assumption of only two plasma modes fails and the transport model has to be solved numerically in the real space, which is not done in this work.…”