Physical review. B./Physical review. B
Magnetic-field control of electric polarization in coupled spin chains with three-site interactions
J. Szṅajd
Abstract
The linear perturbation renormalization group (LPRG) is used to study coupled $XY$ chains with Dzyaloshinskii-Moriya (DM) and three-spin interactions in a magnetic field. Starting with a minimal model exhibiting the magnetoelectric effect, a spin-$\frac{1}{2} XY$ chain with nearest, next-nearest $({J}_{2}^{x})$, and DM $({D}_{1}^{y})$ interactions in a magnetic field, the recursion relations for all effective interactions generated by the LPRG transformation are found. The evaluation of these relations allows us to analyze, among others, the influence of ${J}_{2}^{x},\phantom{\rule{0.16em}{0ex}}{D}_{1}^{y}$, three-spin (${S}_{i}^{x}{S}_{i+1}^{y}{S}_{i+2}^{z}\ensuremath{-}{S}_{i}^{y}{S}_{i+1}^{x}{S}_{i+2}^{z}$), and interchain interactions on the thermodynamic properties. The field and temperature dependences of the polarization, specific heat, and correlation functions are found. It is shown that an interchain coupling triggers a phase transition indicated by the divergence of the renormalized coupling parameters.