Elementary excitations in the ordered phase of spin-1/2 J1-J2 model on square lattice

A. V. Syromyatnikov, A. Yu. Aktersky

We use recently proposed four-spin bond-operator technique (BOT) to discuss spectral properties of frustrated spin-$\frac{1}{2}$ $J_1$--$J_2$ Heisenberg antiferromagnet on square latti…