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Massive and Massless Behavior in Dimerized Spin Ladders

D. C. Cabra·M. D. Grynberg
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Abstract

We investigate the conditions under which a gap vanishes in the spectrum of dimerized coupled spin-1/2 chains by means of Abelian bosonization and Lanczos diagonalization techniques. Although both interchain ($J'$) and dimerization ($δ$) couplings favor a gapful phase, it is shown that a suitable choice of these interactions yields massless spin excitations. We also discuss the influence of different arrays of relative dimerization on the appearance of non-trivial magnetization plateaus.

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D. C. Cabra, M. D. Grynberg. 1999-02-12. Massive and Massless Behavior in Dimerized Spin Ladders. https://doi.org/10.1103/physrevlett.82.1768

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