Year: 2016
Type: article
Abstract: Despite impressive progress in the development of superconducting nanowire single-photon detectors (SNSPD), the main obstacle for the widespread use of such detectors is the low operating temperature required for low-temperature superconductors. The very attractive idea of increasing the operating temperature using high-temperature superconductors for SNSPD fabrication is problematic due to the insufficient quality of ultra-thin films from high-temperature superconductors, which is one of the key requirements for the single-photon detection by superconducting nanowires. In this work, we demonstrate the possibility of fabricating ultra-thin YBa 2 Cu 3 O 7− x films on SrTiO 3 substrates with a surface flatness of ±1 unit cell and a high critical current density up to 14 MA cm −2 at T = 78 K. The critical current density of ultra-thin films had very low value in the first three unit cell layers adjacent to the substrate and reached nearly the bulk value at the fifth layer. 97% of the superconducting current is carried by only two upper layers of a 5-unit-cell thick YBa 2 Cu 3 O 7− x film. Due to such superconducting current distribution over the film thickness and good surface flatness 5-unit-cell thick YBa 2 Cu 3 O 7− x films could be promising for the fabrication of single-photon detectors.
Authors: M Lyatti, A Savenko, U Poppe
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2406010331