The influence of noise on electron dynamics in semiconductors driven by a periodic electric field

Abstract

Studies about the constructive aspects of noise and fluctuations in different non-linear systems have shown that the addition of external noise to systems with an intrinsic noise may result in a less noisy response. Recently, the possibility to reduce the diffusion noise in semiconductor bulk materials by adding a random fluctuating contribution to the driving static electric field has been tested. The present work extends the previous theories by considering the noise-induced effects on the electron transport dynamics in low-doped n-type GaAs samples driven by a high-frequency periodic electric field (cyclostationary conditions). By means of Monte Carlo simulations, we calculate the changes in the spectral density of the electron velocity fluctuations caused by the addition of an external correlated noise source. The results reported in this paper confirm that, under specific conditions, the presence of a fluctuating component added to an oscillating electric field can reduce the total noise power. Furthermore, we find a nonlinear behaviour of the spectral density with the noise intensity. Our study reveals that, critically depending on the external noise correlation time, the dynamical response of electrons driven by a periodic electric field receives a benefit by the constructive interplay between the fluctuating field and the intrinsic noise of the system.

Nonlinear Relaxation Phenomena in Metastable Condensed Matter Systems

“…This counterintuitive effect has been found in different physical areas, ranging from the generation of spin currents [29], aggregation kinetics of Brownian particles [30,31], chemical reaction system [32], translocation dynamics of polymers [33][34][35], ultra-fast magnetization dynamics of magnetic spin systems [36,37], dynamic electron response in zinc-blende semiconductor crystals [38][39][40][41][42][43], noise redistribution in quasi 2D Silicon Mos inversion layers [44], to interdisciplinary physical models [45][46][47][48][49][50][51][52].…”

External Noise Effects in Silicon MOS Inversion Layer

“…In the last decade an increasing interest has been devoted towards possible constructive aspects of noise and fluctuations in physical and biological systems [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. Previous studies have shown that, under specific conditions, an external noise can constructivelly interact with an intrinsically nonlinear system, characterized by the presence of intrinsic noise, giving rise to positive effects [13][14][15] such as stochastic resonance (SR) [16][17][18][19], resonant activation (RA) [20,21] and noise enhanced stability (NES) [22][23][24][25][26].…”

“…Previous studies have shown that, under specific conditions, an external noise can constructivelly interact with an intrinsically nonlinear system, characterized by the presence of intrinsic noise, giving rise to positive effects [13][14][15] such as stochastic resonance (SR) [16][17][18][19], resonant activation (RA) [20,21] and noise enhanced stability (NES) [22][23][24][25][26]. In particular, the possibility to suppress the intrinsic noise in n-type GaAs and Si bulk, driven by a static electric field, with the addition of a Gaussian correlated noise source, has been theoretically investigated [27].…”

“…By using a Monte Carlo approach and including energetic considerations in the theoretical analysis, Varani et al have concluded that the most favourable condition to obtain noise suppression should be found in GaAs for a static electric field around 6.5 kV/cm, corresponding to the maximum variance. Detailed studies of diffusion noise in low-doped GaAs bulk, subjected to a driving periodic electric field containing time-correlated fluctuations, have revealed the possibility of a suppression of electronic noise [24,25]. Under specific conditions, the intrinsic noise in n-type GaAs crystals can be also reduced by adding a two-level random telegraph noise source to the driving high-frequency oscillating electric field [26].…”

“…The suppression arises from the fact that the transport dynamics of electrons in the semiconductor material receives a benefit by the constructive interplay between the fluctuating electric field and the intrinsic noise of the system. This effect can be viewed as a NES phenomenon [24][25][26]. Theoretical works which investigate the possibility to improve the ultra-fast magnetization dynamics of magnetic spin systems by including correlated noise have been published in Refs.…”