A Microscopic Calculation of the Spin-stiffness Constant for the Spin-1/2 Square-Lattice Heisenberg Antiferromagnet.
01 January 1989
We discuss a systematic, microscopic calculation of the spin stiffness constant, rho sub s, for the spin-1/2 square-lattice Heisenberg antiferromagnet. An infinitesimal twist is imposed upon the system by gradually rotating the direction of antiferromagnetic ordering. The difference in the ground state energy of this system with respect to the uniformly ordered ground state can be related to the spin stiffness constant, rho sub s.