Quantum magnonics: when magnon spintronics meets quantum information science

TL;DR

Quantum magnonics merges spintronics and quantum information science, enabling the study of quantum states of magnons and their integration with quantum platforms for advanced information processing and quantum technologies.

Contribution

This paper provides a comprehensive overview of recent advances in quantum magnonics, highlighting new methods for generating, manipulating, and hybridizing magnonic quantum states with various quantum systems.

Findings

Demonstration of quantum states of magnons such as single-magnon and squeezed states

Integration of magnons with quantum platforms like superconducting qubits and photonic cavities

Potential applications in quantum memories and high-precision measurements

Abstract

Spintronics and quantum information science are two promising candidates for innovating information processing technologies. The combination of these two fields enables us to build solid-state platforms for studying quantum phenomena and for realizing multi-functional quantum tasks. For a long time, however, the intersection of these two fields was limited. This situation has changed significantly over the last few years because of the remarkable progress in coding and processing information using magnons. On the other hand, significant advances in understanding the entanglement of quasi-particles and in designing high-quality qubits and photonic cavities for quantum information processing provide physical platforms to integrate magnons with quantum systems. From these endeavours, the highly interdisciplinary field of quantum magnonics emerges, which combines spintronics, quantum optics and quantum information science.Here, we give an overview of the recent developments concerning the quantum states of magnons and their hybridization with mature quantum platforms. First, we review the basic concepts of magnons and quantum entanglement and discuss the generation and manipulation of quantum states of magnons, such as single-magnon states, squeezed states and quantum many-body states including Bose-Einstein condensation and the resulting spin superfluidity. We discuss how magnonic systems can be integrated and entangled with quantum platforms including cavity photons, superconducting qubits, nitrogen-vacancy centers, and phonons for coherent information transfer and collaborative information processing. The implications of these hybrid quantum systems for non-Hermitian physics and parity-time symmetry are highlighted, together with applications in quantum memories and high-precision measurements. Finally, we present an outlook on the opportunities in quantum magnonics.