Improved $\hbox{All-MgB}_{2}$ Toggle Flip-Flop Circuit With Increased Operating Speed and Temperature Range

We have fabricated and tested rapid single flux quantum toggle flip-flop circuits using self-shunted MgB
₂
/ MgO/MgB
₂
Josephson junctions with a single ground layer. The MgB
₂
films were deposited using HPCVD, and the MgO barrier was deposited using DC reactive sputtering. We highlight the circuit's voltage divider operation dependence on current bias and temperature which show operation from 7 to 30 K. The highest attained operating speed is 335 GHz at 7 K. These results demonstrate the versatile temperature range and speed of MgB
₂
digital circuits.