Straddling Regime of a Transmon Qubit

We investigate the straddling regime of a superconducting transmon qubit coupled to a microwave resonator in a circuit QED architecture. In this regime, effects of higher levels of the transmon qubit add constructively to improve single shot measurement. This regime requires significantly lower coupling between qubit and cavity than has previously been reported, but paradoxically, this reduced coupling leads to an increased measurement signal. We report on a qubit designed to substantially reduce coupling and access this straddling regime.