Single particle tunneling spectrum of superconducting Nd<sub>1-x</sub>Sr<sub>x</sub>NiO<sub>2</sub> thin films.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33247088.
- Also identified by DOI 10.1038/s41467-020-19908-1 and PMC identifier 7695741.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The pairing mechanism in cuprates remains as one of the most challenging issues in condensed matter physics. Recently, superconductivity was discovered in thin films of the infinite-layer nickelate Nd<sub>1-x</sub>Sr<sub>x</sub>NiO<sub>2</sub> (x = 0.12-0.25) which is believed to have the similar 3d<sup>9</sup> orbital electrons as that in cuprates. Here we report single-particle tunneling measurements on the superconducting nickelate thin films. We find predominantly two types of tunneling spectra, one shows a V-shape feature which can be fitted well by a d-wave gap function with gap maximum of about 3.9 meV, another one exhibits a full gap of about 2.35 meV. Some spectra demonstrate mixed contributions of these two components. Combining with theoretical calculations, we attribute the d-wave gap to the pairing potential of the [Formula: see text] orbital. Several possible reasons are given for explaining the full gap feature. Our results indicate both similarities and distinctions between the newly found Ni-based superconductors and cuprates.