Fig. 4: Dependence of the high-harmonic yield from β-WP2 on pump orientation.
From: High-harmonic generation in Weyl semimetal β-WP2 crystals
a False-color map of the crystallographic orientation-dependent HHG spectra. Zero degrees corresponds to the pump polarization parallel to the a-axis (Γ–X direction in reciprocal space). The pump intensity was set as ~0.9 TW/cm2 at a wavelength of 1900 nm in the experiment. b Zoomed-in view of the section of the 7th–10th harmonics surrounded by dashed circles in (a). Vertical lines highlight angles of 90°, 180°, and 270°. c, d Polar plots of the respective orientation-dependent strength of odd and even orders. Red lines are the fitting results obtained from Eqs. (5) and (6).
