Magnetostrictive Phononic Frequency Combs

TL;DR

This paper demonstrates a novel magneto-mechanical frequency comb generated via three-wave mixing in a magnetostrictive resonator, with tunable comb spacing and controllable switching, opening new avenues for contactless sensing and wireless applications.

Contribution

It introduces the first experimental realization of magneto-mechanical frequency combs using a macroresonator, including integer and half-integer harmonics, with tunable and switchable features.

Findings

Observed frequency combs in kHz regime with Hz resolution

Demonstrated tunable comb tooth spacing from Hz to kHz

Achieved controllable switching of comb types via bifurcation suppression

Abstract

Magnetostriction, mechanical-to-magnetic or magnetic-to-mechanical response, plays a pivotal role in magneto-mechanical systems. Here, we propose and experimentally demonstrate a magneto-mechanical frequency comb via the three-wave mixing mechanism, which solely requires the involvement of the fundamental mode f0 of a magnetostrictive macroresonator. Two types of combs, i.e., the integer-harmonic combs and the half-integer-harmonic combs, are observed in kHz regime with Hz resolution by magnetically pumping the mm-scale resonator with near-resonant f0. The integer-harmonic combs are centered at lfp, while the half-integer-harmonic combs are centered at (2n - 1) fp/2 resulting from the period-doubling bifurcation of fp. The tooth spacing of both types of combs is determined and can be continuously tuned by changing fs from Hz to kHz. Moreover, the half-integer-harmonic combs can be purposely switched with frequency shifting half a tooth spacing via suppressing period-doubling bifurcation. The experimentally observed formation, evolution, and switching of combs can be well understood by introducing the bias magnetical force and modulated linear stiffness into the Duffing equation. Our findings on magnetically manipulated phononic frequency comb could provide a magneto-mechanical platform for potential non-invasive and contactless sensing and even antenna for wireless operation.