1998/03/24 by Xiaoqun Wang
Physics and Astronomy · #cond-mat.str-el
published as Modern. Phys. Lett. B, 14 2000327 · 8 pages, 6 figures, Revtex
arxiv created 1998/03/24 · arxiv updated 2009/11/30
Using the Density Matrix Renormalization Group method, we determined the phase diagram of a frustrated antiferromagnetic spin-\frac 1 2 ladder at zero temperature. Two spin-gapped phases, the Haldane phase and the singlet phase, are identified. A phase transition between the two phases occurs at any non-zero value of frustration coupling J×. On the phase boundary, the spin gap vanishes for sufficiently small J×. Crossing this non-gapped line, the transition is of second order, while of first order for larger J×. Striking frustration effects are predicted for ladder materials.