A multigigahertz Josephson-semiconductor interface circuit using 77-K differential monolithic HEMT amplifier and 4.2-K JJ high-voltage driver for superconductor-semiconductor electronic hybrid systems. - Naoki Harada; Akira Watanabe; Yuji Awano; Kohki Hikosaka; Naoki Yokoyama (IEEE J. Solid State Circuits, 2000)