New tools to determine the topological character of Shiba chains

Nicholas Sedlmayr (1) , Vardan Kaladzhyan (2) , Cristina Bena (3)

1 UMCS - Maria Curie-Sklodowska University
2 Unibas - Université de Bâle = University of Basel = Basel Universität
3 IPHT - Institut de Physique Théorique - UMR CNRS 3681

We introduce three new analytical and semi-analytical tools that allow one to determine the topological character of impurity Shiba chains. The analytical methods are based on calculating the effective Green's function of an infinite embedded chain using the T-matrix formalism. We thus provide a solution to the longstanding size-effects problem affecting the only general alternative method, the numerical tight-binding analysis. As an example we consider a chain of magnetic impurities deposited on an s-wave superconducting substrate with Rashba spin-orbit and we calculate its topological phase diagram as a function of the magnetic impurity strength and the chemical potential. We find a perfect agreement between all our new techniques and a numerical analysis.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]; Supraconductivité [cond-mat.supr-con]

Nicholas Sedlmayr, Vardan Kaladzhyan, Cristina Bena. New tools to determine the topological character of Shiba chains. 2021. ⟨cea-03196089⟩