Regular fractal structure of the energy matrix in 1D Heisenberg open spin-1/2 chains

F. Pan, Liaoning Normal University
J. P. Draayer, Louisiana State University
L. R. Dai, Liaoning Normal University
D. Zhang, Liaoning Normal University


A permutation group approach to a one-dimensional Heisenberg open spin-1/2 chain with nearest neighbor interactions is studied. Regular fractal structures appear in matrices of the Hamiltonian constructed under the outer-product basis of the permutation group, which enables one to solve the eigenvalue problem in a systematic manner.