TY  - JOUR
AU  - Lyatti, Matvey
AU  - Savenko, Aleksei
AU  - Poppe, Ulrich
TI  - Ultra-thin YBa$_{2}$Cu$_{3}$O$_{7-x}$ films with high critical current density
JO  - Superconductor science and technology
VL  - 29
IS  - 6
SN  - 0953-2048
CY  - Bristol
PB  - IOP Publ.
M1  - FZJ-2017-01294
SP  - 065017
PY  - 2016
AB  - 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 YBa2Cu3O7−x films on SrTiO3 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 YBa2Cu3O7−x film. Due to such superconducting current distribution over the film thickness and good surface flatness 5-unit-cell thick YBa2Cu3O7−x films could be promising for the fabrication of single-photon detectors.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000376268900026
DO  - DOI:10.1088/0953-2048/29/6/065017
UR  - https://juser.fz-juelich.de/record/827096
ER  -