Emergence of superconducting dome in insulating ZrNx films via nitrogen manipulation

TL;DR

This study demonstrates the emergence of a superconducting dome in ZrNx films, resembling high-Tc superconductor phase diagrams, achieved through nitrogen manipulation, combining multiple experimental techniques to explore its electronic properties.

Contribution

It is the first to show a superconducting dome in ZrNx films via nitrogen tuning, linking normal state resistivity and superconductivity to high-Tc superconductor behavior.

Findings

Superconductivity in ZrNx follows BCS theory.

Normal state exhibits Fermi liquid behavior.

Superconducting dome appears near insulating phase.

Abstract

Reproducing the electronic phase diagram of strongly correlated high-transition-temperature (high-Tc) superconductors in materials other than Cu-, Fe-, and Ni-based compounds has been a challenging task. Only very recently, a few material systems have partially achieved this goal by band engineering. In this work, we combine film growth, charge transport, magnetometry, Terahertz Spectroscopy, Raman scattering, and Scanning Transmission Electron Microscopy to investigate superconductivity and the normal state of ZrNx, which reveals a phase diagram that bears extraordinary similarities to those of high-Tc superconductors. Remarkably, even though superconductivity of ZrNx can be characterized within the Bardeen-Cooper-Schrieffer paradigm and its normal state can be understood within the Fermi liquid framework, by tunning the N chemical concentration, we observe the evolution of a superconducting dome in the close vicinity of a strongly insulating state and a normal state resistivity mimics its counterpart of the high-Tc superconductors.