Transition Temperature of a Superconductor under a Helical Magnetic field

Abstract

We consider a bilayer system with a conventional s-wave superconductor and a chiral helimagnet. If we assume that structure of an external magnetic field from the helimagnet is same as the magnetic moment structure in the helimagnet, a helical magnetic field is applied to the superconductor. Our previous simulation showed that vortex structures depend on strongly on structure of the helical magnetic field as well as the amplitude of the field. We study how pitch of the helical magnetic field affects the transition temperature. For this purpose, we formulate the linearized Ginzburg-Landau equation for the helical magnetic field.