Controllable chiral Majorana modes by noncollinear magnetic configuration in a topological Josephson junction

Abstract

We theoretically present controllable chiral Majorana modes (CMMs) by noncollinear magnetic configuration in a Josephson junction on a topological insulator, where two ferromagnetic insulators (FIs) are sandwiched in between two superconductors (SCs). It is shown that an additional phase shift is induced by the different chiralities of the CMMs at the two FI/SC interfaces. Its magnitude is determined by the misorientation angle θ , which can result in the 0 − π state transition and ϕ _0 supercurrent. Particularly, due to the selective equal spin Andreev reflection, the coexistence of fully spin-polarized spin-triplet and -singlet correlations is exhibited. However, for the two magnetizations only along the y -axis, there exist no additional phase shift and the 100% supercurrent magnetoresistance can be exhibited. The results can be employed to not only identify the topological SCs but also design a perfect topological supercurrent spin valve device.

Keywords

• chiral Majorana modes
• noncollinear magnetic configuration
• topological Josephson junction