Tunable Magnon Interactions in a Ferromagnetic Spin-1 Chain

Prashant Chauhan, Fahad Mahmood, Hitesh J. Changlani, S. M. Koohpayeh, and N. P. Armitage
Phys. Rev. Lett. 124, 037203 – Published 23 January 2020
PDFHTMLExport Citation

Abstract

NiNb2O6 is an almost ideal realization of a 1D spin-1 ferromagnetic Heisenberg chain compound with weak unidirectional anisotropy. Using time-domain THz spectroscopy, we measure the low-energy electrodynamic response of NiNb2O6 as a function of temperature and external magnetic field. At low temperatures, we find a magnonlike spin excitation, which corresponds to the lowest energy excitation at q0. At higher temperatures, we unexpectedly observe a temperature-dependent renormalization of the spin-excitation energy, which has a strong dependence on field direction. Using theoretical arguments, exact diagonalizations, and finite temperature dynamical Lanczos calculations, we construct a picture of magnon-magnon interactions that naturally explains the observed renormalization. We show how magnetic field strength and direction may be used to directly tune the sign of the magnon-magnon interaction. This unique scenario is a consequence of the spin-1 nature and has no analog in the more widely studied spin-1/2 systems.

  • Figure
  • Figure
  • Figure
  • Received 15 July 2019
  • Revised 7 October 2019

DOI:https://doi.org/10.1103/PhysRevLett.124.037203

© 2020 American Physical Society

Physics Subject Headings (PhySH)

Condensed Matter, Materials & Applied Physics

Authors & Affiliations

Prashant Chauhan1, Fahad Mahmood1,*,‡, Hitesh J. Changlani2,3,1,†, S. M. Koohpayeh1, and N. P. Armitage1

  • 1The Institute for Quantum Matter, Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA
  • 2Department of Physics, Florida State University, Tallahassee, Florida 32306, USA
  • 3National High Magnetic Field Laboratory, Tallahassee, Florida 32304, USA

  • *fahad@illinois.edu
  • hchanglani@fsu.edu
  • Present address: Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3080, USA

Article Text (Subscription Required)

Click to Expand

Supplemental Material (Subscription Required)

Click to Expand

References (Subscription Required)

Click to Expand
Issue

Vol. 124, Iss. 3 — 24 January 2020

Reuse & Permissions
Access Options
CHORUS

Article Available via CHORUS

Download Accepted Manuscript
Author publication services for translation and copyediting assistance advertisement

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Letters

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×