Unconventional superconductivity induced in Nb films by adsorbed chiral molecules


  Hen Alpern  ,  Eran Katzir   ,  Shira Yochelis  ,  Nadav Katz  ,  Yossi Paltiel  ,  Oded Millo  
racah institute of physics - Hebrew University

Motivated by recent observations of chiral-induced magnetization and spin-selective transport we studied the effect of chiral molecules on conventional BCS superconductors. By applying scanning tunneling spectroscopy, we demonstrate that the singlet-pairing s-wave order parameter of Nb is significantly altered upon adsorption of chiral polyalanine alpha-helix molecules on its surface. The tunneling spectra exhibit zero-bias conductance peaks embedded inside gaps or gap-like features, suggesting the emergence of unconventional triplet-pairing components with either d-wave or p-wave symmetry, as corroborated by simulations. These results may open a way for realizing simple superconducting spintroinics devices.

I will also briefly discuss a related issue, the triggering of p-wave superconductivity in graphene proximity coupled to the electron-doped cuprate superconductor Pr2-xCexCuO4.