Ballistic magnon heat conduction and possible Poiseuille flow in the helimagnetic insulator Cu${}_2$OSeO${}_3$

Abstract

We report on the observation of magnon thermal conductivity ${\kappa }_m\sim$ 70 W/mK near 5 K in the helimagnetic insulator Cu${}_2$OSeO${}_3$, exceeding that measured in any other ferromagnet by almost two orders of magnitude. Ballistic, boundary-limited transport for both magnons and phonons is established below 1 K, and Poiseuille flow of magnons is proposed to explain a magnon mean-free path substantially exceeding the specimen width for the least defective specimens in the range 2 K $<T<$ 10 K. These observations establish Cu${}_2$OSeO${}_3$ as a model system for studying long-wavelength magnon dynamics.

10pp, 9 figures, accepted PRB (Editor's Suggestion)

References in corpus (5)

• Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
• Ferrimagnetism of the magnetoelectric compound Cu${}_2$OSeO${}_3$ probed by ${}^{77}$Se NMR
• Electrical detection of spiral spin structures in Pt|Cu_2OSeO_3 heterostructures
• Establishing the fundamental magnetic interactions in the chiral skyrmionic Mott insulator Cu2OSeO3 by terahertz electron spin resonance
• Thermal drag revisited: Boltzmann versus Kubo

Cited by in corpus (5)

• Magnonic topological insulators in antiferromagnets
• Laser control of magnonic topological phases in antiferromagnets
• Asymmetric quantum shot noise in magnon transport
• Universal $1/3$-suppression of magnonic shot noise in diffusive insulating magnets
• Seeded Chemical Vapor Transport Growth of Cu${}_2$OSeO${}_3$