Noise enhanced spontaneous chaos in semiconductor superlattices at room temperature

TL;DR

This paper demonstrates that noise can enhance spontaneous chaos in semiconductor superlattices at room temperature, making them promising for high-speed true random number generation.

Contribution

It reveals that internal and external noises broaden voltage ranges and improve robustness of chaos in superlattices at room temperature, a novel finding for nanotechnology applications.

Findings

Spontaneous chaos observed at room temperature in superlattices.

Noise broadens voltage ranges for chaotic oscillations.

Chaos robustness is increased by internal and external noise.

Abstract

Physical systems exhibiting fast spontaneous chaotic oscillations are used to generate high-quality true random sequences in random number generators. The concept of using fast practical entropy sources to produce true random sequences is crucial to make storage and transfer of data more secure at very high speeds. While the first high-speed devices were chaotic semiconductor lasers, the discovery of spontaneous chaos in semiconductor superlattices at room temperature provides a valuable nanotechnology alternative. Spontaneous chaos was observed in 1996 experiments at temperatures below liquid nitrogen. Here we show spontaneous chaos at room temperature appears in idealized superlattices for voltage ranges where sharp transitions between different oscillation modes occur. Internal and external noises broaden these voltage ranges and enhance the sensitivity to initial conditions in the superlattice snail-shaped chaotic attractor thereby rendering spontaneous chaos more robust.