Origin of the Colossal Electromagnon in Multiferroic RMnO3 @ University of Maryland

Author(s): R. Valdés Aguilar1, M. Mostovoy2, A. B. Sushkov1, C. L. Zhang3, Y. J. Choi3, S-W. Cheong3, and H. D. Drew1 1Department of Physics, University of Maryland, College Park, Maryland 20742, USA 2Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, The Netherlands 3Rutgers Center for Emergent Materials and Department of Physics & Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA

In multiferroic materials, where magnetism and ferroelectricity coexist, it is possible to excite mixed spin and lattice vibrations with electromagnetic waves called electromagnons. We find that the mechanism responsible for electromagnons is different from the one that couples static magnetism and ferroelectricity. Our results show how the strong coupling of spin and lattice excitations produce the colossal electromagnon observed in RMnO₃. This mechanism can also exist in non-multiferroic materials.

Above: Displacements of the oxygen ions (pink) modulates the super exchange between Mn ions (blue) which couples the magnons with the phonons.

Related publication(s):

1. Physical Review Letters, 102, 047203 (2009)