Calibration for single-qubit gates using robust phase estimation

Constructing single-qubit unitary gates with high accuracy is necessary for most implementations of gate-based quantum computation. A crucial component of this task is gate calibration, which requires methods for measuring the discrepancies between actual, physical gate implementations and ideal gates. In this talk we describe improved practical methods for quantifying such discrepancies using robust phase estimation, which requires only weak assumptions about the initial accuracies of the gate implementations.