Fig. 2: Phonon frequency combs in CrGeTe3 and its field dependence.
From: Spontaneously formed phonon frequency combs in van der Waals solid CrGeTe3 and CrSiTe3
a, b Detailed views of the \({A}_{{{{\rm{g}}}}}^{5}\) mode of CrGeTe3 in the parallel-polarization channel, data collected with 633 nm and 532 nm lasers respectively. All peak fits in this work are Voigt profile fits with a fixed Gaussian part equal to the instrumental resolution (see “Methods”). c Comparison of frequency combs between LL and RR polarization, showing similar patterns and intensities. d Linear fit of the comb energy as a function of the peak index. The fitting uncertainty is smaller than the size of the markers shown. e Magnetic field dependence of the frequency combs observed in the \({A}_{{{{\rm{g}}}}}^{5}\) mode.
