Magnetic impurities on superconducting Pb surfaces

Density-functional description of materials for topological qubits and superconducting spintronics

“…21 Measurements by Ruby et al 30 of Mn impurities on Pb(110) confirm that the main spectroscopic signature is found close to the coherence peak of Pb. This was recently also found theoretically by Wu et al, 22 where it was pointed out that the exact position of YSR peaks at the surface depends sensitively on relaxations of the distance of the impurity to the surface. However, in the bulk, where we place our impurities, the impurities experience a higher coordination number of neighboring host atoms which will generally reduce the effects of lattice relaxations.…”

“…The form of the pairing potential is an approximation introduced by Suvasini et al, 24 who introduced the set of effective coupling constants λ i . The different λ i are allowed to vary in the different sites i of a computational unit cell which enables the description of inhomogeneous systems consisting of superconductors and non-superconductors such as magnets, 19,22 normal metals, 14,15,18,33 or topological insulators. 16,17 In the KKR formalism it is straight-forward to include the BdG formalism where using multiple-scattering theory the Green's function for the KS-BdG Hamiltonian, Eq.…”

“…It was successfully used to study conventional s-wave superconductors, [10][11][12][13] heterostructures of s-wave superconductors and nonsuperconductors, [14][15][16][17][18] or impurities embedded into superconductors. [19][20][21][22] In this work we focus on recent developments in the KS-BdG method using the parameter-based approach. This was combined with the Korringa-Kohn-Rostoker Green function formalism (KKR) based on multiplescattering theory, 23 founded on the seminal work of Suvasini et al 24 Recently, the KS-BdG approach was also implemented into the open-source JuKKR code, 25 that allows a full-potential relativistic description of complex materials.…”

Topological superconductivity from first principles. I. Shiba band structure and topological edge states of artificial spin chains

“…This is allowed by the Green's-function-based solution of the Kohn-Sham-Dirac-Bogoliubov-de Gennes (KSDBdG) equations [59,60]. On the one hand, it has been demonstrated previously that many aspects of STM experiments are reproducible by such calculations [60][61][62][63], while on the other hand, it allows us to calculate other quantities, such as spin-polarization and the superconducting order parameter (OP) [64], which are important to understand the nature of these states. Furthermore, some of their properties can be further explored and tested by computational experiments which go beyond the capabilities of conventional experimental techniques.…”