Unconventional superconductivity and magnetic-related states induced in a conventional superconductor by nonmagnetic chiral molecules

abstract:

The effect of chiral molecules (CHM) adsorbed on conventional singlet-pairing s-wave superconductors was the subject of recent works. Scanning tunnelling microscopy measurements revealed in-gap zero bias conductance peaks (ZBCP) in tunnelling spectra acquired from CHM/Nb hybrid systems, suggesting an induced unconventional order parameter in the Nb surface. NbSe₂ flakes with adsorbed chiral molecules demonstrated either ZBCPs or multiple in-gap peaks shifting with magnetic field as Shiba states. Our most recent work employs Muon spin rotation (µSR) measurements to measure the magnetic field depth profile on Nb films with and without adsorbed chiral molecules. The results of these measurements are consistent with triplet superconductivity arising due to a spin active interface between the chiral molecules layer and the Nb film. From all the above, it becomes evident that chiral molecules induce unconventional triplet superconductivity on conventional superconductors which originates on the surface but decays deep into the bulk.