Interferometric control of magnon-induced nearly perfect absorption in cavity magnonics

Abstract

The perfect absorption of electromagnetic waves has promoted many applications, including photovoltaics, radar cloaking, and molecular detection. Unlike conventional methods of critical coupling that require asymmetric boundaries or coherent perfect absorption that require multiple coherent incident beams, here we demonstrate single-beam perfect absorption in an on-chip cavity magnonic device without breaking its boundary symmetry. By exploiting magnon-mediated interference between two internal channels, both reflection and transmission of our device can be suppressed to zero, resulting in magnon-induced nearly perfect absorption (MIPA). Such interference can be tuned by the strength and direction of an external magnetic field, thus showing versatile controllability. Furthermore, the same multi-channel interference responsible for MIPA also produces level attraction (LA)-like hybridization between a cavity magnon polariton mode and a cavity photon mode, demonstrating that LA-like hybridization can be surprisingly realized in a coherently coupled system.

Unveiling Pump induced Magnon Mode via its Strong Interaction with Walker Modes

“…We then address the power dependence of the anticrossing, which shows that this effect is not an intrinsic property like the cavity magnon polariton [17][18][19][20][21][22][23][24][25][26][27][28], but an effect induced by the strong pump. To this end, we set ω d /2π = 3.4 GHz and vary the pump power P d from −30 to 20 dBm.…”

“…It leads to the formation of polaritonic quasiparticles, lays the foundation for coherent energy transfer between distinct physical entities [11][12][13], and affects strongly the quantum transport. Typical examples of this kind of elementary excitations in magnets are magnon polaron [14][15][16] and cavity magnon polariton [17][18][19][20][21][22][23][24][25][26][27][28], which are described by the coupled harmonic oscillators â and b of frequency ω a and ω b with a coupling strength |g| as…”

Superfluid-Mott insulator quantum phase transition in a cavity optomagnonic system

“…In addition, the strong coupling between cavity photon and magnon has been observed at both low and high temperature experimentally [50]. Based on these features of cavity optomagnonic system, many intriguing phenomena have been explored, such as magnon dark modes and gradient memory [51], coher-ent and dissipative magnon-photon interaction [52][53][54][55][56][57][58][59], the high-order sideband generation [60], the self-sustained pscillations and chaos [61][62][63], non-Hermitian physics [55,64,65], entanglement [66][67][68][69][70], magnon-induced nearly perfect absorption [71], magnon Fock state [72], magnon squeezing [73] and so on. Recently, several novel progresses associated with the photon blockade in cavity optomagnonic system are also investigated [74,75,76].…”

Strong Long-Range Spin-Spin Coupling via a Kerr Magnon Interface

“…Among various quantum interfaces including superconducting circuits [9,10], phonons [11][12][13][14][15][16][17][18][19][20], critical polaritons [21,22], sqeezed photons [23,24] and optomechanics [25][26][27], the emerged magnons [28][29][30][31][32] (i.e., the energy quanta of spin waves) in magnetical materials have played an essential role in quantum physics [33][34][35][36][37][38][39][40][41][42][43][44][45], with different types of magnets such as sphere magnets [46][47][48][49] and film layer magnets [50][51][52][53]. Due to the small mode volume and high spin density of the Kittel mode in a yttrium-iron-garnet (YIG) sphere magnet, magnons can be strongly coupled to other quantum systems [54]…”