Noise-enhanced spontaneous chaos in semiconductor superlattices at room temperature Articles uri icon

published in

  • EPL  Journal

publication date

  • August 2014

start page

  • 1

end page

  • 6

issue

  • 3(37002)

volume

  • 107

international standard serial number (ISSN)

  • 0295-5075

electronic international standard serial number (EISSN)

  • 1286-4854

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.

keywords

  • gass/alas superlattices; coherence resonance; time-series; fluctuations; dimension; dynamics; lasers; domain