Effects of spin-elastic interactions in frustrated Heisenberg antiferromagnets

The Heisenberg antiferromagnet on a compressible triangular lattice in the spin-wave approximation is considered. It is shown that the interaction bet ween quantum fluctuations and elastic degrees of freedom stabilize the low symmetric L phase with a collinear Neel magnetic ordering. A multivalued de pendence of the on-site magnetization as a function of an uniaxial pressure is found.