Resonant control of stochastic spatio-temporal dynamics in a tunnel diode by multiple time delayed feedback

TL;DR

This paper demonstrates how multiple time-delayed feedback can effectively control noise-induced spatio-temporal patterns in a resonant tunnelling diode, enhancing oscillation coherence and stability.

Contribution

It introduces a novel control method using multiple time delays that improves resonance effects and stability in noise-driven semiconductor dynamics.

Findings

Resonant features of noise-induced oscillations are enhanced with multiple delays.

Optimal delay times significantly increase oscillation coherence.

The control method enlarges the stable dynamical regime without bifurcations.

Abstract

We study the control of noise-induced spatio-temporal current density patterns in a semiconductor nanostructure (double barrier resonant tunnelling diode) by multiple time-delayed feedback. We find much more pronounced resonant features of noise-induced oscillations compared to single time feedback, rendering the system more sensitive to variations in the delay time $\tau$. The coherence of noise-induced oscillations measured by the correlation time exhibits sharp resonances as a function of $\tau$, and can be strongly increased by optimal choices of $\tau$. Similarly, the peaks in the power spectral density are sharpened. We provide analytical insight into the control mechanism by relating the correlation times and mean frequencies of noise-induced breathing oscillations to the stability properties of the deterministic stationary current density filaments under the influence of the control loop. Moreover, we demonstrate that the use of multiple time delays enlarges the regime in which the deterministic dynamical properties of the system are not changed by delay-induced bifurcations.