Publication Date:
2018-04-28
Description:
Author(s): S. Gao, K. Guratinder, U. Stuhr, J. S. White, M. Mansson, B. Roessli, T. Fennell, V. Tsurkan, A. Loidl, M. Ciomaga Hatnean, G. Balakrishnan, S. Raymond, L. Chapon, V. O. Garlea, A. T. Savici, A. Cervellino, A. Bombardi, D. Chernyshov, Ch. Rüegg, J. T. Haraldsen, and O. Zaharko A remarkable feature of the excitation spectrum of chromite spinels, where antiferromagnetically coupled Cr 3 + ions form a highly frustrated pyrochlore lattice, is the existence of so-called resonance modes. These resonances resemble the zero-energy modes that have been theoretically predicted for the pyrochlore Heisenberg antiferromagnet and other highly frustrated systems. Here, the authors investigate the complicated structural and magnetic states in MgCr 2 O 4 spinel, interpret the magnetic excitations as acoustic and optical spin wave branches, and show that the neutron scattering cross sections of transitions within a unit of two corner-sharing tetrahedra match the observed intensity distribution of the resonances. [Phys. Rev. B 97, 134430] Published Fri Apr 27, 2018
Keywords:
Magnetism
Print ISSN:
1098-0121
Electronic ISSN:
1095-3795
Topics:
Physics
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