Terahertz mixing in MgB₂ microbolometers

The authors report on a terahertz (600 GHz) mixing experiment with Mg B2 microbolometers in the resistive state. The authors observed that for a 20 nm film a mixer gain bandwidth of 2.3 GHz can be achieved, corresponding to an energy relaxation time of 70 ps. The experimental results were analyzed using a two-temperature model. As a result, the phonon escape time of ∼20 ps was deduced. At 1.6 THz the Mg B2 mixer uncorrected noise temperature was 11 000 K. The obtained results show that Mg B2 bolometers are good prospects for the terahertz range as both broadband mixers and fast direct detectors.