Possibility of a pi Josephson junction and switch in superconductors with spiral magnetic order - art. no. 104503

It is shown in tunneling junctions made of two magnetic superconductors wit h spiral magnetic order that the Josephson current depends on the magnetic phase, theta = theta (L)-theta (R), as well as the spiral helicity, chi = c hi (L)chi (R). The former describes the relative orientation of magnetizati ons on the left (L) and right (R) banks of the contact, while the latter ch aracterizes the left (right)-handed spiral with respect to the surface unit vector. The Josephson current J = (J(c) - J-(chi) cos theta )sin phi is ca lculated as a function of the superconducting order parameters, Delta (L(R) ), the exchange energies, h(L(R)), and the spiral wave vectors, Q(L(R)). It turns out that the pi Josephson junction can he realized in some range of microscopic parameters. A possibility of making switches, which are based o n this new phase relation, is also analyzed.