28 May 2014
A way to generate high-frequency chaos
Microwave devices have already many practical applications in a number of key technologies including radars, security scanners and wireless communications. Nowadays, chaotic high-frequency (GHz-THz) oscillators are in strong demand in fast random-number generators, chaos-based communication systems and logics. However, in contrast to the optical frequency range, chaotic sub- and terahertz generators are still underdeveloped.
Loughborough physicists, Dr. K. Alekseev, Dr. A.G. Balanov, Dr. M. Gaifullin and Prof. F.V. Kusmartsev, together with their colleagues from the Saratov State University and the University of Nottingham found a simple way to control a character of the current oscillations in a semiconductor superlattice device. They shown both theoretically and in experiment that a linear resonator can dramatically affect the charge transport in the superlattice, and thus its high-frequency output. Being coupled to an ordinary linear resonator, like stripline, the device becomes sensitive to the applied voltage, whose value defines periodic, quasi-periodic or even chaotic character of the generated current.
These results were recently published in Physical Review Letters [Phys. Rev. Lett. 112, 116603 (2014)]