Yu-Shiba-Rusinov bands in ferromagnetic superconducting diamond

Abstract

The combination of different exotic properties in materials paves the way for the emergence of their new potential applications. An example is the recently found coexistence of the mutually antagonistic ferromagnetism and superconductivity in hydrogenated boron-doped diamond, which promises to be an attractive system with which to explore unconventional physics. Here, we show the emergence of Yu-Shiba-Rusinov (YSR) bands with a spatial extent of tens of nanometers in ferromagnetic superconducting diamond using scanning tunneling spectroscopy. We demonstrate theoretically how a two-dimensional (2D) spin lattice at the surface of a three-dimensional (3D) superconductor gives rise to the YSR bands and how their density-of-states profile correlates with the spin lattice structure. The established strategy to realize new forms of the coexistence of ferromagnetism and superconductivity opens a way to engineer the unusual electronic states and also to design better-performing superconducting devices.

Full orbital decomposition of Yu-Shiba-Rusinov states based on first principles

“…This is further strengthened by the fact that the position of the in-gap states is at best described qualitatively with simple models even for the dominant e g and t 2g resonances. With the introduction of more impurities we could investigate the hybridization of the YSR resonances resulting in the formation of YSR bands [29,30]. Similarly, the use of the KKR framework will enable us to extend the method to concentrated alloys exploiting the coherent potential approximation (CPA) as outlined previously [31][32][33].…”

Full orbital decomposition of Yu-Shiba-Rusinov states based on first principles

“…With the introduction of more impurities we could investigate the hybridisation of the YSR resonances resulting in the formation of YSR bands. [28,29] Similarly, the use of the KKR framework will enable us to extend the method to concentrated alloys exploiting the coherent potential approximation (CPA) as outlined previously. [30][31][32] Finally, the incorporation of the fully relativistic BdG equations [19] including spin-orbit coupling will, in a next step, enable us to investigate the existence of Majorana zero modes [33][34][35][36] at the surface of conventional superconductors.…”

Evolution of the Andreev bands in the half-filled superconducting periodic Anderson model

“…Another example of such system is the hydrogenated superconducting graphene [29] where individual hydrogens interact ferromagnetically when deposited on the graphene and can give rise to in-gap Andreev bands. Also, recent experiments involving superconducting boron-doped diamond coated with ferromagnetic hydrogen monolayer [30,31] show the existence of Andreev bands and regions of high zero-bias conductance.…”