Inducing Superconductivity in Ni-Pb Surface Alloy by Proximity Effect

Yen-Hui Lin^1*, Chia-Ju Chen¹, Deng-Sung Lin¹, Pin-Jui Hsu¹

¹Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Yen-Hui Lin, email:a9011905@hotmail.com

Majorana fermion, a new type of exotic quasiparticle state has been reported on topological superconductors whereas the Abrikosov vortex can possibly host Majorana zero energy mode. In this work, we successfully fabricate Ni-Pb surface alloy by depositing Ni on Pb(111) at elevated temperature. According to structure model, Ni-Pb alloy shows a hexagonal-like arrangement with an atomic composition of Ni₄Pb₃. From dI/dU spectra, the superconducting gap of Ni-Pb surface alloy has been observed and the gap size is slightly narrower than pristine Pb(111) substrate. With an external magnetic field applied, the superconducting gap of Ni-Pb surface alloy has been found to disappear at 40 mT. Such superconducting Ni-Pb surface alloy may serve as an interesting candidate for the emergence of Majorana zero mode in future study.

Keywords: Superconductivity, Scanning Tunneling Spectroscopy, Nickel, Lead, Majorana Zero Energy Mode