Rectification of terahertz radiation in semiconductor superlattices in the absence of domains

Abstract

Abstract. We study theoretically the dynamical rectification of a terahertz ac electric field, i.e. the dc current and voltage response to the incident radiation, in strongly coupled semiconductor superlattices. We address the problem of stability against electric field domains: A spontaneous dc voltage is known to appear exactly for parameters for which a spatially homogeneous electron distribution is unstable. We show that by applying a weak direct current bias the rectifier can be switched from a zero dc voltage state to one with a finite voltage in full absence of domains. The switching occurs near the conditions of dynamical symmetry breaking of an unbiased semiconductor superlattice. Therefore our scheme allows for the generation of dc voltages that would otherwise be unreachable due to domain instabilities. Furthermore, for realistic, highly doped wide miniband superlattices at room temperature the generated dc field can be nearly quantized, that is, be approximately proportional to an integer multiple of ω/ea where a is the superlattice period and ω is the ac field frequency.

Lyapunov stability of charge transport in miniband semiconductor superlattices

“…Thus, the models considered in this paper take into account application of various fields used in a range of experimental [29][30][31][32][33] and theoretical works. 6,34,35 We analytically and numerically show that when the electron transport in the SL is static, the method demonstrates good agreement with the nL criterion, conventionally used for the prediction of electric domain instability. 36 We also show that the application of an ac voltage and a tilted magnetic field to the SL results in a variety of periodic, quasiperiodic, and even chaotic spatiotemporal charge dynamics.…”

Devil's staircase, spontaneous-DC bias, and chaos via quasiperiodic plasma oscillations in semiconductor superlattices

“…Since here the ndc appears at zero dc voltage, a region of absolute negative conductivity (anc) is always associated with its appearance. This leads to dynamical rectification [13,16], an effect that is studied in detail elsewhere [4,5,15,17]. We refer to the saddle-type instability as the ndc-instability.…”