Cooperative polariton dynamics in feedback-coupled cavities

• Published in: Nature communications Vol. 8; no. 1; pp. 1437 - 6
• Main Authors: Yao, Bimu, Gui, Y. S., Rao, J. W., Kaur, S., Chen, X. S., Lu, W., Xiao, Y., Guo, H., Marzlin, K. -P., Hu, C. -M.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10-11-2017; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/119; 639/766/400/2797; 639/766/400/482; Cavities; Feedback; Harmonic oscillators; Holes; Humanities and Social Sciences; multidisciplinary; Oscillators; Physics; Polaritons; Quantum theory; Rabi frequency; Science; Science (multidisciplinary); Spin dynamics; Spintronics
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-017-01796-7

The emerging field of cavity spintronics utilizes the cavity magnon polariton (CMP) induced by magnon Rabi oscillations. In contrast to a single-spin quantum system, such a cooperative spin dynamics in the linear regime is governed by the classical physics of harmonic oscillators. It makes the magnon Rabi frequency independent of the photon Fock state occupation, and thereby restricts the quantum application of CMP. Here we show that a feedback cavity architecture breaks the harmonic-oscillator restriction. By increasing the feedback photon number, we observe an increase in the Rabi frequency, accompanied with the evolution of CMP to a cavity magnon triplet and a cavity magnon quintuplet. We present a theory that explains these features. Our results reveal the physics of cooperative polariton dynamics in feedback-coupled cavities, and open up new avenues for exploiting the light–matter interactions.
Rabi oscillations of magnons typically do not have few photon control of single spin quantum systems. Here, the authors use a feedback cavity architecture to increase magnon-photon cooperativity, enabling increased control of light-matter interactions in magnonic systems via cooperative polariton dynamics.