Enhanced Cooper pairing in nano-patterned metals

We study the effect of nano-patterning on the superconductivity of Aluminum

nano-films, focusing on periodically patterned circular holes. Using the De-

bye model, we calculate the phonon band structure for both bulk and patterned

nano-films and show that nano-patterning increases the phonon density of states

through the softening of the modes. This increase translates to enhancement in

Eliashberg function and electron-phonon coupling strength. Through numerical

simulations using commercially available software, we find optimal patterning

geometries that maximize the enhancement in superconducting transition tem-

perature. Our study shows that introducing the nano-patterning to the bulk

can enhance the transition temperature up to 6%, providing a potential route

for further studying the enhancement of Tc in nanoscale metallic systems.