Events in Physics

Spin-triplet superconductors: interface to ferromagnets and magnetic edge states

In this talk I will discuss two remarkable effects of spin-triplet superconductors (TSC): i) the spin-orbital coupling emerging at the interface with an itinerant ferromagnet (FM) [2], ii) the occurrence of magnetic Andreev states at their edge if the system allows for singlet pairing in a subdominant channel [3].

In a TSC-FM heterostructure, the orientation of the FM moment relative to the TSC vector order parameter is a crucial variable that controls the physical behavior. For a single-component p-wave TSC, we find that the variation of the gap controls the orientation of the FM's moment mainly via the change in condensation energy. When the interface is imperfect or spin active the scenario is different and other processes can play the decisive role in setting the magnetic profile [5].

Concerning the surface states, novel magnetic effects can occur if triplet and singlet pairing get mixed and have a non-uniform spatial profile. As a result, the Andreev bound states are spin-polarized, leading to a finite surface magnetization, spin current and surface charge currents that exhibit anomalous dependence on the magnetization [3].

[1] See for instance Y. Maeno, S. Kittaka, T. Nomura, S. Yonezawa, K. Ishida, J. Phys. Soc. Jpn. 81, 011009 (2012) and references therein.

[2] P. Gentile, M. Cuoco, A. Romano, C. Noce, D. Manske, P. M. R. Brydon, Phys. Rev. Lett. 111, 097003 (2013).

[3] A. Romano, P. Gentile, C. Noce, I. Vekhter, M. Cuoco, Phys. Rev. Lett. 110, 267002 (2013).

[4] P. M. R. Brydon, Phys. Rev. B 80, 224520 (2009); P. M. R. Brydon, Y. Asano, and C. Timm, Phys. Rev. B 83, 180504(R) (2011).

[5] D. Terrade, P. Gentile, M. Cuoco, and D. Manske, Phys. Rev. B 88, 054516 (2013).