Low frequency oscillations and bifurcation diagram in semi-insulating GaAs samples

Abstract

We present an experimental study of bifurcation diagrams from low frequency current oscillations (LFO) measurements obtained from semi-insulating GaAs samples grown by low temperature molecular beam Epitaxy (LT-MBE). The considered growth temperatures were 215˚C and 265˚C. LFO are considered to be spontaneously generated oscillations under constant applied bias V . These oscillations were measurement and recorded in the form of time series. The bifurcation diagrams were obtained from the sequence of minima as a function of the applied bias. The standard measurement procedure was described elsewhere. As the control parameter, the bias allows the identification of a bifurcation route to chaos.

High Resolution Parameter-Space from a Two-Level Model on Semi-Insulating GaAs

“…This structure established a direct communication between the windows in order within chaotic regions, producing new routes of bifurcation. These intricate self-organized patterns were experimentally observed in the literature [da Silva et al, 2004;Rubinger et al, 2003;Albuquerque et al, 2003;da Silva et al, 2006da Silva et al, , 2009, but still needed a full theoretical description of how they emerge, what their size is in the parameter-space, if they have a fractal structure, based on the new model presented.…”

“…(10)-(13) are the smallest tested set that still produces the NNDC region, and take into account the main SI-GaAs physical properties [da Silva et al, 2004;Rubinger et al, 2003;Albuquerque et al, 2003;da Silva et al, 2006]. Furthermore, for simulations, the smallest set of equations that still reproduces all physical phenomena is important, in order to reduce the computational cost.…”

“…It is possible to incorporate as many other mechanisms, as one wishes, into the present model, but they may become superfluous and therefore have very little effect on the final results, because the g-r rate equation chosen, eqs. (10)(11)(12)(13) are the smallest set tested that still produces the NNDC region, and take into account the main SI-GaAs physical properties [1][2][3]26]. Furthermore, for simulations the smallest set of equations that still reproduces all physical phenomena is important, in order to reduce the computational cost.…”