Frequency transitions in phononic four-wave mixing

This work builds upon the recent demonstration of a phononic four-wave mixing (FWM) pathway mediated by parametric resonance. In such a process, drive tones f_d1 and f_d2 associated with a specific phonon mode interact such that one of the drive tones also parametrically excites a second mode at a sub-harmonic frequency and such interactions result in a frequency comb f_d1/2 +/- n(f_d1-f_d2 ). However, the specific behaviour associated with the case where both drive tones can independently excite the sub-harmonic phonon mode has not been studied or previously described. While it may be possible to expect the merger of two frequency combs f_d1/2 +/- n(f_d1-f_d2 ) and f_d2/2 +/- n(f_d1-f_d2 ), this paper indicates that only one of these mechanisms is selected and also shows an interesting transition linked to this process. Such frequency transitions from f_d1/2 +/- n(f_d1-f_d2 ) to f_d2/2 +/- n(f_d1-f_d2 ) holds potential promise for computing applications.