Transport properties of ultrathin BaFe1.84Co0.16As2 superconducting nanowires

TL;DR

This study reports the fabrication and characterization of ultrathin BaFe1.84Co0.16As2 superconducting nanowires, revealing promising transport properties for potential use in high-temperature superconducting single-photon detectors.

Contribution

First demonstration of ultrathin BaFe1.84Co0.16As2 nanowires with detailed transport property analysis for superconducting applications.

Findings

High critical temperature T_c0=20 K

High critical current density J_c=1.8E7 A/cm^2 at 10 K

Narrow transition width of 2.5 K

Abstract

Superconducting nanowire single-photon detectors (SNSPDs) have an absolute advantage over other types of single photon detectors except the low operating temperature. Therefore, many efforts have been devoted to find high-temperature superconducting materials that are suitable for preparing SNSPDs. Copper-based and MgB2 ultra-thin superconducting nanowires have been already reported. However, the transport properties of iron-based ultra-thin superconducting nanowires have not been studied. In this work, a 10 nm thick 200 nm wide 30 {\mu}m long high quality superconducting nanowire was fabricated from ultrathin BaFe1.84Co0.16As2 films by a lift-off process. The precursor BaFe1.84Co0.16As2 film with a thickness of 10 nm and root-mean-square roughness of 1 nm was grown on CaF2 substrates by pulsed laser deposition. The nanowire shows a high superconducting critical temperature Tzero c=20 K with a narrow transition width of Delta T=2.5 K and exhibits a high critical current density Jc of 1.8E7 A/cm2 at 10 K. These results of ultrathin BaFe1.84Co0.16As2 nanowire will attract interest in electronic applications, including SNSPDs