Nonreciprocal double-carrier frequency combs in cavity magnonics

We propose a scheme for realizing strongly nonreciprocal double-carrier frequency combs in three-mode cavity magnonic system consisting of two microwave cavities and a yttrium iron garnet sphere with magnon Kerr nonlinearity. The nonreciprocal microwave frequency comb (MWFC) and magnonic frequency comb (MFC) can be simultaneously implemented due to the asymmetrical nonlinear response in two different directions. We first show high tunability of nonreciprocal MWFC and MFC based on independent sideband in the situation of single input probe field. By properly operating the input fields, the perfect nonreciprocity of comb in a broad frequency range (nonreciprocity of number of comb) and ultrahigh isolation ratio (nonreciprocity of intensity of comb) are obtained. We prove that the tooth spacing of frequency comb can be flexibly modulated by adjusting the beat frequency between the probe field and the control field, the fraction-order comb thereby is generated, which unlocks the full potential for producing high resolution frequency comb. More importantly, it is find that the sideband mixing emerges for the situation of double input probe fields. The hybridized MWFC and the hybridized MFC further are formed, which enhances greatly nonreciprocity of fraction-order comb. These consequently give rise to the simultaneous achievement of high resolution and strong nonreciprocity of double-carrier frequency combs. Our proposal provides an effective avenue for the manipulation of the nonreciprocity and resolution of MWFC and MFC, and has potentially practical applications in precision measurement and integrated quantum technology.