The Double-Time Green's Function Approach to the Two-Dimensional Heisenberg Antiferromagnet with Broken Bonds

Yun Song, H. Q. Lin, Jue-Lian Shen

We improved the decoupling approximation of the double-time Green's function theory, and applied it to study the spin-$\frac{1}{2}$ two-dimensional antiferromagnetic Heisenberg mode…