Enhancing Chaotic Behavior at room temperature in GaAs/(Al,Ga)As Superlattices

TL;DR

This paper demonstrates that shorter GaAs/(Al,Ga)As superlattices with higher barriers exhibit stronger, faster, and more robust chaotic electronic behavior at room temperature, enhancing their potential for true random number generation.

Contribution

It shows that reducing superlattice length and increasing potential barriers enhances deterministic chaos, improving random number generation capabilities at room temperature.

Findings

Shorter superlattices exhibit fully chaotic dynamics.

Chaos frequency is higher in shorter superlattices.

Chaotic behavior persists without stochastic processes.

Abstract

Previous theoretical and experimental work has put forward 50-period semiconductor superlattices as fast, true random number generators at room temperature. Their randomness stems from feedback between nonlinear electronic dynamics and stochastic processes that are intrinsic to quantum transitions. This work theoretically demonstrates that shorter superlattices with higher potential barriers contain fully chaotic dynamics over several intervals of the applied bias voltage compared to the 50-periods device which presented a much weaker chaotic behavior. The chaos arises from deterministic dynamics, hence it persists even in the absence of additional stochastic processes. Moreover, the frequency of the chaotic current oscillations is higher for shorter superlattices. These features should allow for faster and more robust generation of true random numbers.