Self-Similar Optical Absorption Spectra in High Magnetic Fields
P. Vogl, C. Strahberger · physica status solidi (b) · 2002
Employing a non-perturbative multi-band approach within empirical tight-binding theory, we show that the magneto-absorption spectrum of a periodic two and three-dimensional electron system possesses a structure that overall reflects the fractal Hofstadter butterfly eigenvalue spectrum. For small magnetic fields, the standard magneto-optical selection results of envelope theory are recovered. We predict that the Hofstadter butterfly can be directly observed by interband magneto-absorption from an undoped GaAs quantum well beneath a periodic array of stressors.