Novel nonreciprocal acoustic effects in antiferromagnets
Institut für Physik, Universität Dortmund - 44221 Dortmund, Germany
2 Department of Physics, Brookhaven National Laboratory Upton, New York 11973-5000, USA
Accepted: 18 November 1998
The possible occurrence of nonreciprocal acoustic effects in antiferromagnets in the absence of an external magnetic field is investigated using both i) a microscopic formulation of the magnetoelastic interaction between spins and phonons and ii) symmetry arguments. We predict for certain antiferromagnets the existence of two new nonreciprocal (non-time invariant) effects: A boundary-condition–induced nonreciprocal effect and the occurrence of transversal phonon modes propagating in opposite directions having different velocities. Estimates are given and possible materials for these effects to be observed are suggested.
PACS: 72.55.+s – Magnetoacoustic effects / 73.50.Rb – Acoustoelectric and magnetoacoustic effects / 85.70.Ec – Magnetostrictive, magnetoacoustic, and magnetostatic devices
© EDP Sciences, 1999