Hybrid magnonics: physics, circuits and applications for coherent information processing

Abstract

Hybrid dynamic systems have recently gained interests with respect to both fundamental physics and device applications, particularly with their potential for coherent information processing. In this perspective, we will focus on the recent rapid developments of magnon-based hybrid systems, which seek to combine magnonic excitations with diverse excitations for transformative applications in devices, circuits and information processing. Key to their promising potentials is that magnons are highly tunable excitations and can be easily engineered to couple with various dynamic media and platforms. The capability of reaching strong coupling with many different excitations has positioned magnons well for studying solid-state coherent dynamics and exploiting unique functionality. In addition, with their gigahertz frequency bandwidth and the ease of fabrication and miniaturization, magnonic devices and systems can be conveniently integrated into microwave circuits for mimicking a broad range of device concepts that have been applied in microwave electronics, photonics and quantum information. We will discuss a few potential directions for advancing magnon hybrid systems, including on-chip geometry, novel coherent magnonic functionality, and coherent transduction between different platforms. As future outlook, we will discuss the opportunities and challenges of magnonic hybrid systems for their applications in quantum information and magnonic logic.

Introduction to spin wave computing

“…The strong coupling of magnons and cavity microwave photons is one of the routes toward quantum magnonics, which is intensively explored nowadays. [429][430][431][432][433][434][435] In addition to single-magnon operations expected to be realized at mK temperatures, macroscopic quantum states such as magnon Bose-Einstein Condensates (BECs) at room temperature have also been considered potential data carriers. The fundamental phenomenon of Bose-Einstein condensation has been observed in different systems of both real particles and quasiparticles.…”

Direct Imaging of Resonant Phonon-Magnon Coupling

“…Spin waves and their quasiparticles, i.e., magnons, are promising for high frequency information procession and transmission [1][2][3][4][5][6] and logic devices [1,7,8]. Unfortunately, the efficient generation of spin wave can be difficult and spin waves also propagate typically only over limited distances of <1 μm for most materials due to magnetic losses [9,10].…”

Sensing chiral magnetic noise via quantum impurity relaxometry

“…Introduction-Magnons -quanta of spin wave excitations -are fundamental to the understanding of the dynamical properties of magnetically ordered materials. This understanding forms the basis for creating nextgeneration classical and hybrid quantum technologies in magnonics (an emerging field utilizing magnons as information carriers) [1][2][3], potentially enabling magnonmediated coherent control [4] and coupling of distant quantum spins [5]. In addition, topological qubit platforms, typically, involve magnetic materials [6] which could introduce an additional source of decoherence.…”

“…Here, the free energy density describing the ferromagnetic thin film includes the Zeeman, exchange, and dipole-dipole energy terms and is given by 2 where H ext is the external field, A ex is the exchange constant, M s is the saturation magnetization, m is the magnetization unit vector, and H D is the demagnetization field [32]. We find the magnetic susceptibility in response to h (in the magnet frame) by solving the linearized-LLG in Fourier domain about the equilibrium magnetization giving δm i (ω, k) = S ij (ω, k)h j (ω, k).…”