Damping of magnons in a two-dimensional S = {1}/{2} Heisenberg antiferromagnet

摘要: Abstract The spin excitation damping is examined for a singlet state of 2D antiferromagnet on square lattice using the rotationally invariant approach two-time Green functions. It shown that lowest boundary weakly damped waves has scale k order ( T 0 ) 3 2 . This leads to an inverse correlation L−1 which much larger than L −1 ∼ exp given by Dyson-Maleev formalism.