Tunable Current Mirror Qubits: Experimental Status

In the last few years significant progress has been made in the development of tunable current-mirror qubits. This novel qubit type is projected to exhibit high coherence due to its insensitivity to environmental noise. However, as a consequence of their noise immunity, tunable current-mirror qubits are also insensitive to control signals, requiring novel control approaches. This talk reviews the successful demonstration of current-mirror test structures that share the same ‘Mobius’ capacitance connectivity as current-mirror qubits. The collective modes of these test structures exhibit a mode frequency parity effect such that even modes are much higher in frequency than odd modes—an indicator that such circuits can generate a parity valve effect—strong double-vortex hopping relative to single-vortex hopping—a key requirement for generating noise insensitivity. This talk also describes design optimizations of current-mirror qubits, and gives a status report on coherence tests, including tests that utilize adiabatic protection sweeps.