5 years ago

Nature of spin excitations in a magnetization plateau.

H. D. Zhou, M. Mourigal, Z. Lu, Tao Hong, J. Ma, Y. Qiu, L. Ge, C. D. Batista, E. S. Choi, H. B. Cao, M. Matsuda, D. L. Quintero-Castro, Y. Kamiya

Magnetization plateaus in quantum magnets---where bosonic quasiparticles crystallize into emergent spin superlattices---are spectacular yet simple examples of collective quantum phenomena escaping classical description. While magnetization plateaus have been observed in a number of spin-1/2 antiferromagnets, the description of their magnetic excitations remains an open theoretical and experimental challenge. Here, we investigate the dynamical properties of the triangular-lattice spin-1/2 antiferromagnet Ba$_3$CoSb$_2$O$_9$ in its 1/3 magnetization plateau phase using a combination of nonlinear spin-wave theory and neutron scattering measurements. The excellent agreement between our theoretical treatment and the experimental data demonstrates that magnons behave semiclassically in the plateau in spite of the purely quantum origin of the underlying magnetic structure. This allows for a quantitative determination of Ba$_3$CoSb$_2$O$_9$ exchange parameters. We discuss the implication of our results to the strong deviations from semiclassical behavior observed in the zero-field spin dynamics of the same material and conclude they must have an intrinsic origin.

Publisher URL: http://arxiv.org/abs/1701.07971

DOI: arXiv:1701.07971v3

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.