EVIDENCE FOR PERIODIC SCAR PATTERNS IN THE WAVE-FUNCTIONS OF A CHAOTIC QUANTUM-WELL

The tunnelling characteristics of GaAs/(AlGa)As double barrier structu res are investigated when a large tilted magnetic field is applied to generate strongly chaotic (nonintegrable) classical motion in the wide (similar to 100 nm) quantum well. In this regime, a transfer-Hamilton ian approach is used to calculate current-voltage characteristics I(V) for the structures. The theoretical I(V) curves reveal a distinct ser ies of resonant peaks which have been observed in recent experiments. These resonances are shown to originate primarily from dominant transi tions into subsets of regularly spaced energy levels in the well whose wavefunctions contain regions of high probability density (scars) alo ng the paths of particular unstable periodic classical orbits. The eff ects of very high magnetic fields (up to 37 T) on the tunnelling chara cteristics are investigated experimentally.