Fig. 3

(a) Schematics of a PAT process involving absorption/emission of multiple photons (photon energy = \({\hslash\:}\omega\:\)), whose original peak is plotted by a black line at the bottom as a Gaussian peak. (b) PAT simulation based on Eq. (1). Original Gaussian peak (peak position at the Fermi level) with FWHM width of 20 µV (I) and 100 µV (II, III) are changed with the RF of \({\hslash\:}\omega\:\)=41.3 µV (I, II) and 4.13 µV (III), whose eV_AC is 250 µV (I, II, III). (c) A plot of the square of the Bessel function (J_l(eV_AC/ℏω))² vs. l assuming eV_AC/ℏω = 100.