Instability zones of periodic 1-dimensional Schrödinger and Dirac operators
Instability zones of periodic 1-dimensional Schrödinger and Dirac operators
The spectra of Schrödinger and Dirac operators with periodic potentials on the real line have a band structure, that is, the intervals of continuous spectrum alternate with spectral gaps, or instability zones. The sizes of these zones decay, and the rate of decay depends on the smoothness of the potential. …