Transition excitation of surface polaritons by a moving charge on antiferromagnet

Excitation of surface polaritons (phonons and magnons) by a charged particle, moving from vacuum into antiferromagnetic material, is studied in the paper. Electromagnetic field and intensity expressions are obtained and analysed in detail for various real and virtual modes. Strong excitations are shown to be possible at certain frequencies, different for phonons and magnons. In contrast to transition radiation of free electromagnetic fields, the energy of polariton field excited by a relativistic particle is independent of the Lorentz factor. (C) 2004 Elsevier B.V. All rights reserved.