Abstract

Superconducting spintronics has emerged in the last decade as a promising new field that seeks to open a new dimension for nanoelectronics by utilizing the internal spin structure of the superconducting Cooper pair as a new degree of freedom. Currently, the discipline finds itself at the crossroads for developing first-generation devices. Among the basic units of superconducting spintronics are the so-called superconducting spin valves. These are nanodevices in which the superconducting current is controlled through the spin degree by changing the magnetization of magnetic elements. We propose a superconducting spin-triplet valve, which consists of a superconductor and an itinerant magnetic material, with the magnet showing an intrinsic non-collinear order characterized by a wave vector that may be aligned in a few equivalent preferred directions under the control of a weak external magnetic field. Re-orienting the spiral direction allows one to controllably modify long-range spin-triplet superconducting correlations, leading to spin-valve switching behaviour. Our results indicate that the spin-valve effect may be noticeable [1]. This bilayer may be used as a magnetic memory element for cryogenic nanoelectronics. It has the following advantages in comparison to superconducting spin valves proposed previously: (i) it contains only one magnetic layer, which may be more easily fabricated and controlled; (ii) its ground states are separated by a potential barrier, which solves the “half-select” problem of the addressed switch of memory elements.

[1] N. G. Pugach, M. Safonchik, T. Champel, M. E. Zhitomirsky, E. Lahderanta, M. Eschrig, and C. Lacroix. Appl. Phys. Lett. 111, 162601 (2017).