Spin-Peierls-like phases in magnetoelastic J1−J2 antiferromagnetic chains at 1/3 magnetization

H. D. ROSALES; G. L. ROSSINI

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

Americal Physical Society

Lugar: New York; Año: 2007 vol. 76 p. 224404 - 224410

0163-1829

We investigate elastic deformations of spinS=1/2 antiferromagnetic J_1-J_2 Heisenberg chains, at M=1/3magnetization, coupled to phonons in the adiabatic approximation.Using a bosonization approach we predict the existence ofnon-homogeneous trimerized magnetoelastic phases. A rich groundstate phase diagram is found, including classical and quantumplateau states for the magnetic sector as well as inequivalentlattice deformations within each magnetic phase. The analyticalresults are supported by exact diagonalization of small clusters.