Enhanced Cooper pairing in nano-patterned metals

TL;DR

This paper proposes a nano-patterning scheme to enhance the superconducting transition temperature in phonon-mediated nano-film superconductors by softening vibrational modes and increasing the density of states, leading to a few percent improvement.

Contribution

The study introduces a novel nano-patterning approach to increase $T_c$ in superconducting films by manipulating vibrational modes, supported by finite element simulations and theoretical analysis.

Findings

Nano-patterning softens vibrational modes in films.

Density of states at high energies increases with patterning.

Superconducting transition temperature $T_c$ is enhanced by a few percent.

Abstract

Nano-patterning has been shown to be a powerful tool for manipulating the vibrational modes of elastic structures, with applications such as optical-mechanical mode coupling. Inspired by these recent developments in phononic band engineering, we propose a nano-patterning scheme to enhance the superconducting transition temperature $T_c$ in phonon-mediated nano-film superconductors, such as aluminum. Using the finite element method, we simulate the lattice vibrational modes of nano-patterned films within the Debye model. Our results show that periodic nano-patterning softens the lattice vibrational modes compared to bulk films. It also increases the density of states at high energies, resulting in a couple of percent enhancement in $T_c$. Moreover, we investigate connections to Weyl's law and provide an experimental design prescription to optimize nano-patterning for further enhancement of the superconducting transition temperature.