Fig. 3: Probing the structural dependence of multiple conduction bands.
From: Observation of light-driven band structure via multiband high-harmonic spectroscopy
a, Oscillation phase as a function of harmonic number, for different crystal orientations ranging from 0° (dark blue) to 45° (cyan). The dashed line marks the cutoff of the first conduction band and the dashed box emphasizes the H21 oscillation phases for different orientations (plotted in b). b, Harmonic 21 (H21, purple) and harmonic 11 (H11, grey) oscillation phase as a function of crystal orientation. c, Two-dimensional second bandgap, ϵc2,v = ϵc2 − ϵv, as a function of crystal momentum (top). The purple contour represents the H21 energy along different crystal orientations. Two-dimensional first bandgap, ϵc1,v = ϵc1,v − ϵv, as a function of crystal momentum (bottom). The grey contour represents H11 energy along different crystal orientations. d, One-dimensional cut of the second (yellow) and first (blue) bandgap along crystal orientations of 10° and 45°. H21 and H11 energies are represented by the purple and grey dashed lines, as well as their crossing point with the bandgaps (cross markers).
