Quantum chaos in resonant tunneling diodes

Resonant tunneling spectroscopy is used to study the electronic energy levels of a wide potential well when a strong magnetic field is applied at an angle θ to the normal to the plane of the well. Even though the classical motion of electrons in the potential well is chaotic in the tilted field geometry, the current-voltage characteristics reveal distinct series of quasi-periodic resonances. The voltage range and period of each series of resonances change dramatically with θ. We explain this behavior by considering the unstable periodic orbits within the chaotic sea of the potential well.