Chiral symmetry and scale invariance breaking in spin chains

Abstract

The effects of the Dzyaloshinsky-Moriya interaction on finite size one-dimensional (1D) magnetic chains are investigated as a function of their length. The magnetic configuration the system adopts for varying boundary conditions are explored analytically, which leads to the appearance of chiral configurations that play a crucial role. The coercive and exchange bias fields show an unexpected chain length dependence, caused by the boundary conditions and by chiral symmetry breaking, which in turn leads to the breakdown of scale-invariance. Our treatment yields results in agreement with experimental evidence and ongoing research on phthalocyanine iron chains bonded to hydrogen.