Intrinsic hysteresis due to the surface barrier for chiral solitons in monoaxial chiral helimagnets

Abstract

Chiral solitons in monoaxial chiral magnets undergo a surface barrier, which is analogous to the Bean-Livingston barrier in type-II superconductors. The authors argue here that the surface barrier is the main mechanism for large hysteresis observed in magnetoresistance (MR) measurements on micrometer-sized samples of CrNb${}_{3}$S${}_{6}$. In the MR hysteresis, a conspicuous jump is observed at the field ${H}_{\mathrm{b}}$ for decreasing fields. Experimental results for ${H}_{\mathrm{b}}\ensuremath{\sim}0.4{H}_{\mathrm{c}}$ (with thermodynamic critical field ${H}_{\mathrm{c}}$) and the theoretical result ${H}_{\mathrm{b}}/{H}_{\mathrm{c}}=4/{\ensuremath{\pi}}^{2}$ are in good agreement with each other. The surface barrier is regarded as a common property of systems (superconductors, chiral magnets, and chiral liquid crystals) that exhibit continuous transitions of the nucleation type.