High-T_c YBCO nanowires for detector applications

YBa₂Cu₃O_7-d (YBCO) is a promising high-T_c material for the fabrication of superconducting detectors with ultimate sensitivity and ultra-fast response in a broad spectral range. Due to its intrinsic interaction times of less than 2 ps the timing jitter of the response of superconducting YBCO nanowire single-photon detectors (SNSPD) should be smaller than in NbN SNSPDs. The design of a SNSPD made from YBCO requires the patterning of meander lines with widths of the nanowire below 300 nm. The required thickness of the YBCO films ranges from a few nanometers for the absorption of optical photons up to several hundred nanometers in the X-ray range. We will present results on the development of a technology for YBCO nanowires with thicknesses below 40 nm, widths of a few hundred nanometers and lengths up to tens of micrometres. The superconducting transport properties of different nanowire geometries measured with and without applying a magnetic field will be presented.