Concentric transmon qubit featuring fast tunability and an anisotropic magnetic dipole moment

摘要: We present a planar qubit design based on superconducting circuit that we call concentric transmon. While employing straightforward fabrication process using Al evaporation and lift-off lithography, observe lifetimes coherence times in the order of 10us. systematically characterize loss channels such as incoherent dielectric loss, Purcell decay radiative losses. The implementation gradiometric SQUID loop allows for fast tuning transition frequency therefore full tomographic control quantum circuit. Due to large size, presented architecture features strongly increased magnetic dipole moment compared conventional transmon designs. This renders promising candidate establish site-selective passive direct Z coupling between neighboring qubits, being pending quest field simulation.