Effects of stochastic webs on chaotic electron transport in semiconductor superlattices

Phys Rev Lett. 2001 Jul 23;87(4):046803. doi: 10.1103/PhysRevLett.87.046803. Epub 2001 Jul 10.

Abstract

We investigate chaotic electron transport in the lowest miniband of a semiconductor superlattice with a tilted magnetic field. This experimentally accessible non-Kolmogorov-Arnol'd-Moser system involves only stationary electric and magnetic fields, but is dynamically equivalent to a time-dependent kicked harmonic oscillator. The onset of chaos strongly delocalizes the electron orbits, thus raising the electrical conductivity. When the cyclotron and Bloch frequencies are commensurate, the phase space is threaded by a stochastic web, which produces a further resonant increase in the conductivity.