Anisotropic effects in antiferromagnetic curvilinear spin chains

Curvilinear spin chains are simplest antiferromagnetic systems revealing direct influence of their shape onto magnetic states via geometry-tracking anisotropies stemming from the dipolar interaction [1] or local surrounding [2]. Here, we show that in addition to the strongest effect onto magnetic state from exchange (biaxial anisotropy and chiral energy term) [1], the local break of the translational symmetry in curvilinear anisotropic antiferromagnets leads to (i) the longitudinal Dzyaloshinskii-Moriya energy term stemming from the single-ion anisotropy and (ii) the local weakly ferromagnetic response [2]. Furthermore, non-zero curvature κ can drive the helimagnetic phase transition in the spin-flop phase and enables the intermediate canted state for rings with large enough κ. [1] O. Pylypovskyi, D. Kononenko et al., Nano Lett. 20, 8157 (2020); [2] O. Pylypovskyi et al., Appl. Phys. Lett. 118, 182405 (2021); [3] Y. Borysenko et al., Phys. Rev. B, 106, 174426 (2022).