Generation of Ultra-Broadband Frequency Comb in Strongly Bistable Nonlinear Magnonic Resonator

TL;DR

This paper demonstrates a novel method for generating ultra-broadband magnonic frequency combs using a highly nonlinear, miniaturized resonator that produces over 350 lines across 450 MHz, with tunable spacing and low power.

Contribution

It introduces a new mechanism for broadband magnonic frequency combs utilizing bistability and parametric excitation in a miniaturized resonator, surpassing prior bandwidth and tunability limits.

Findings

Over 350 comb lines generated spanning 450 MHz bandwidth

Comb spacing is continuously tunable via a two-tone external drive

Achieved order-of-magnitude enhancement over previous methods at low power

Abstract

Magnonic frequency combs (MFCs) offer a promising route to compact, energy-efficient platforms for on-chip coherent microwave signal generation and processing. Conventional on-chip comb generation typically relies on nonlinear resonators supporting a series of equidistant, low-loss resonances driven by a strong monochromatic signal, resulting in fixed comb spacing defined by the resonator's free spectral range (FSR). Here we introduce and experimentally demonstrate a fundamentally different mechanism for ultrabroadband MFC generation using a highly nonlinear miniaturized magnonic resonator. The small resonator volume, combined with a slow-wave transducer, yields high intra-resonator power density, driving the system deep into the bistable regime where parametric excitation of propagating spin waves facilitates comb formation. Our approach yields more than 350 comb lines spanning a 450 MHz bandwidth, with spacing continuously tunable via a two-tone external drive, representing an order-of-magnitude enhancement over prior reports while operating at relatively low power. The platform is ultra-compact (4-6 orders of magnitude smaller in size than conventional YIG sphere resonators), fully scalable, and highly tunable, enabling precise control of comb properties through magnetic bias and pump manipulation. These results establish a new paradigm for frequency comb technology, unlocking transformative opportunities in microwave signal processing, neuromorphic computing, and precision sensing.