MgB2 HEB Mixers at Operation Temperatures above Liquid Helium Temperature

Paper in proceeding, 2016

In this paper we discuss results of MgB2 thin films deposition for the hot-electron bolometer (HEB) application. For this purpose a custom made hybrid physical-chemical vapour deposition (HPCVD) system was built. For films thicknesses d in the 15-45nm range the critical temperatures were from 34K to 40K. For bridges as narrow as 500nm the critical current density was >107A/cm2 indicating a high film quality. The intermediate frequency (IF) gain bandwidth (GBW) was measured at 0.4THz at various temperatures and bias points. The GBW follows the 1/d trend and is at least 6GHz for the 15nm thick sample.