## Abstract

We show that, as a consequence of the fact that the Bogoliubov transformation mixes spin waves on different sublattices, the phenomenological Loudon Hamiltonian describing the two spin-wave absorption in rutile antiferromagnets also predicts a linear Stark effect on the two spin-wave line in these materials in the presence of dc electric fields. We present calculated line shapes for ir absorption in a dc field. The dc field needed to observe significant effects is of order 10^{6} V/cm. The Stark-effect experiment could be used to measure the parameter of the Loudon Hamiltonian, which is of interest from a theoretical point of view, since some mechanisms of two spin-wave absorption predict π_{2}=0. The Stark effect also provides the possibility in principle of producing a phase transition in these antiferromagnets by the application of a dc electric field. This is the case because the shift in the spin-wave energy produced by the dc field can be negative for some values of k. We study this possibility in a simple approximation. The required fields are too large to be realizable in rutile antiferromagnets but there is some hope of observing such transitions in other kinds of antiferromagnets.

Original language | English (US) |
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Pages (from-to) | 987-988 |

Number of pages | 2 |

Journal | Journal of Applied Physics |

Volume | 40 |

Issue number | 3 |

DOIs | |

State | Published - 1969 |