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Re-entrant Behavior and Gigantic Response in Disordered Spin-Peierls System

Hitoshi Seo·Yukitoshi Motome·Naoto Nagaosa
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Abstract

Effects of disorder and external field on the competing spin-Peierls and antiferromagnetic states are studied theoretically in terms of the numerical transfer matrix method applied to a quasi one-dimensional spin 1/2 Heisenberg model coupled to the lattice degree of freedom. We show that, at temperatures above the impurity-induced antiferromagnetic phase, inhomogeneous spin-Peierls lattice distortions remain to exist showing a re-entrant behavior. This feature can be drastically altered by very weak perturbations, e.g., the staggered magnetic field or the change in interchain exchange coupling $J_\perp$, leading to a huge response, which is analogous to the colossal magnetoresistance phenomenon in perovskite manganese oxides.

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Hitoshi Seo, Yukitoshi Motome, Naoto Nagaosa. 2004-06-17. Re-entrant Behavior and Gigantic Response in Disordered Spin-Peierls System. https://doi.org/10.1103/physrevb.70.060403

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