Title: Deung-Jang, Choi: Spin correlation on superconducting surfaces studied by scanning tunneling microscope
Number: 55/17
Status: Closing date exceeded
Begin: Thursday, December 07, 2017 at 02:00PM
Tutor: Václav Holý
Location: Lecture room F2, Facutly of Mathematics and Physics, First floor Ke Karlovu 5, Prague 2


Thursday, 7.12. 2017, 14.00,

Lecture room F2 (1st floor), MFF UK, Ke Karlovu 5


Deung-Jang, Choi

Donostia International Physics Center (DIPC)
Centro de Fisica de Materiales, CFM/MPC (CSIC-UPV/EHU), CIC nanoGUNE ,
Donostia-San Sebastian 20018, Spain
E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it


Spin correlation on superconducting surfaces studied by scanning tunneling microscope


Recently, the introduction of new impurity states in the superconducting gap has received a lot of attention. Indeed, the search of a new superconducting state dubbed topological supercon-ductivity is strongly based in the combination of doping classical (s-wave) superconductors with magnetic impurities that arrange in a chiral fashion. Depending on the nature of the atomic species added to a superconductor, different effects can be achieved. Magnetic adatoms can be considered as impurities that weaken the binding of superconducting Cooper pairs leading to dirty superconductivity and to impurity levels in the gap: so-called Yu-Shiba-Rusinov (YSR) states. These YRS states are the results of weakening Cooper pairs by the localized magnetic moment of the impurity. By using scanning tunneling spectroscopy and resolving their origin and exploring basic properties of BCS superconductors, we found that the shape of YSR states reflects the shape of d atomic orbitals [1]. And also in this work, we present the first results of controlled single-atom manipulation to assemble a chain of Cr atoms on a Bi2Pd superconduc-tor. The influence of the atoms on the superconducting electronic structure is revealed as well as the interactions at work. The interatomic distance between two Cr atoms is thoroughly ex-plored revealing Cr-Cr interactions mediated by the superconductor for the first time [2]. Fur-thermore, we have extended our studies to spin chains of Cr on Bi2Pd, finding interesting so-lutions of YSR extended states, precursors of YSR bands.
[1] Choi, D.-J. et al. Mapping the orbital structure of impurity bound states in a superconduc-tor. Nat. Commun. 8, 15175 (2017).
[2] Choi, D.-J. et al. arXiv:1709.09224