Complex magnetic structure and spin waves of the noncollinear antiferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>Mn</mml:mi></mml:mrow><mml:mn>5</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mi>Si</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub></mml:math>
Nikolaos Biniskos, Flaviano José dos Santos, K. Schmalzl, S. Raymond, Manuel dos Santos Dias, J. Perßon, Nicola Marzari, Stefan Blügel, Samir Lounis, Thomas Brückel
Abstract
Frustrated antiferromagnets can feature a wide variety of noncollinear magnetic ground states. The resulting states have been associated with anomalous transport properties and interesting thermodynamic phenomena. Here, by combining inelastic neutron scattering measurements and density functional theory calculations, the authors investigate the complex ground state of Mn${}_{5}$Si${}_{3}$, its evolution under magnetic field, and its spin excitation spectrum. Furthermore, they model the instability of some Mn magnetic moments in a frustrated environment to unveil their behavior under an external field. This general model can be potentially applied to several frustrated antiferromagnets.