Field-induced decay dynamics in square-lattice antiferromagnets

Dynamical properties of the square-lattice Heisenberg antiferromagnet in applied magnetic field are studied for arbitrary value S of the spin. Above the threshold field for two-particle decays, the standard spin-wave theory yields singular corrections to the excitation spectrum with logarithmic divergences for certain momenta. We develop a self-consistent approximation applicable for S≥1, which avoids such singularities and provides regularized magnon decay rates. Results for the dynamical structure factor obtained in this approach are presented for S=1 and S=5/2.


Published in:
Physical Review B Condensed Matter, 82, 14, 144402
Year:
2010
ISSN:
0163-1829
Keywords:
Laboratories:




 Record created 2010-12-02, last modified 2018-03-17


Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)