Discovery of the classical Bose-Einstein condensation of magnons in solid antiferromagnets

Results of experiments in which the Bose-Einstein condensate of magnons is created in the CsMnF$_3$ easy-plane antiferromagnet in a system with coupled nuclear-electron precession with dynamical frequency shift are presented. This condensate is similar to the Bose-Einstein condensate of magnons in superfluid $^3$He-A in aerogel.