Magnetization plateaux and jumps in a class of frustrated ladders: A simple route to a complex behaviour
نویسندگان
چکیده
We study the occurrence of plateaux and jumps in the magnetization curves of a class of frustrated ladders for which the Hamiltonian can be written in terms of the total spin of a rung. We argue on the basis of exact diagonalization of finite clusters that the ground state energy as a function of magnetization can be obtained as the minimum with Maxwell constructions if necessary of the energies of a small set of spin chains with mixed spins. This allows us to predict with very elementary methods the existence of plateaux and jumps in the magnetization curves in a large parameter range, and to provide very accurate estimates of these magnetization curves from exact or DMRG results for the relevant spin chains. PACS numbers: 75.10.Jm, 75.40.Cx, 75.45.+j, 75.60.Ej Typeset using REVTEX A Feodor-Lynen fellow of the Alexander von Humboldt-foundation. Present address: Institut für Theoretische Physik, TU Braunschweig, 38106 Braunschweig, Germany. 1
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