Controlling superconductivity of CeIrIn$_5$ microstructures by substrate selection

TL;DR

This paper introduces an improved finite-element model to predict and control the superconducting transition temperature in CeIrIn$_5$ microstructures by selecting appropriate substrates to manipulate strain fields, enabling advanced superconductor structuring.

Contribution

An improved finite-element model is developed to accurately predict superconductivity in CeIrIn$_5$ microstructures based on substrate-induced strain, facilitating precise control over superconducting properties.

Findings

Model reliably predicts Tc in complex structures

Substrate selection tailors strain fields effectively

Fabricated microstructures validate the model's accuracy

Abstract

Superconductor/metal interfaces are usually fabricated in heterostructures that join these dissimilar materials. A conceptually different approach has recently exploited the strain sensitivity of heavy-fermion superconductors, selectively transforming regions of the crystal into the metallic state by strain gradients. The strain is generated by differential thermal contraction between the sample and the substrate. Here, we present an improved finite-element model that reliably predicts the superconducting transition temperature in CeIrIn$_5$ even in complex structures. Different substrates are employed to tailor the strain field into the desired shapes. Using this approach, both highly complex and strained as well as strain-free microstructures are fabricated to validate the model. This enables full control over the microscopic strain fields, and forms the basis for more advanced structuring of superconductors as in Josephson junctions.