Demonstrated control of a Transmon using a Reciprocal Quantum Logic digital circuit - Part 1

We report on experiments in which we used a Reciprocal Quantum Logic circuit to perform Z rotations on a Transmon qubit. Reciprocal Quantum Logic (RQL) [1] is a low-power superconducting digital technology based on pairs of single-flux quantum voltage pulses. Here we discuss the RQL hardware used in these experiments - an RQL output amplifier [2]~ whose output is non-return-to-zero (NRZ) encoded 3 mV differential signal, and is primarily intended for transmitting RQL data signals to standard room temperature CMOS hardware. We demonstrate the circuit operation at both 4 K and 20 mK with wide circuit operating margins. [1] J. Appl. Phys\textbf{ 109}, 103903 (2011) [2] Supercond. Sci. Technol.\textbf{ 23}, 022044 (2010)