Title
Interrogating the superconductor Ca(PtAs)(FePtAs) Layer-by-layer
Document Type
Article
Publication Date
10-14-2016
Abstract
Ever since the discovery of high-T superconductivity in layered cuprates, the roles that individual layers play have been debated, due to difficulty in layer-by-layer characterization. While there is similar challenge in many Fe-based layered superconductors, the newly-discovered Ca(PtAs)(FeAs) provides opportunities to explore superconductivity layer by layer, because it contains both superconducting building blocks (FeAs layers) and intermediate PtAs layers. Cleaving a single crystal under ultra-high vacuum results in multiple terminations: an ordered PtAs layer, two reconstructed Ca layers on the top of a PtAs layer, and disordered Ca layer on the top of FeAs layer. The electronic properties of individual layers are studied using scanning tunneling microscopy/spectroscopy (STM/S), which reveals different spectra for each surface. Remarkably superconducting coherence peaks are seen only on the ordered Ca/PtAs layer. Our results indicate that an ordered structure with proper charge balance is required in order to preserve superconductivity.
Publication Source (Journal or Book title)
Scientific reports
First Page
35365
Recommended Citation
Kim, J., Nam, H., Li, G., Karki, A. B., Wang, Z., Zhu, Y., Shih, C., Zhang, J., Jin, R., & Plummer, E. W. (2016). Interrogating the superconductor Ca(PtAs)(FePtAs) Layer-by-layer. Scientific reports, 6, 35365. https://doi.org/10.1038/srep35365