Optimization of single shot readout of a transmon qubit using a SLUG microwave amplifier

We report on measurement of a superconducting transmon qubit using a number of optimization techniques and a low noise amplifier. ~Optimization is performed over power and frequency, and a genetic algorithm is employed to optimize the readout fidelity as a function of the measurement pulse shape. ~In addition, a superconducting low-inductance undulatory galvanometer (SLUG), a SQUID-based microwave amplifier, is used to reduce system noise. ~The SLUG amplifier has very high dynamic range and low noise over a relatively wide frequency range. ~Both the SLUG amplifier and genetic algorithm lead to improved readout fidelity over analytic pulse shaping and HEMT amplification.