Operation of a high-frequency, phase slip qubit

Aluminum-based Josephson junctions (JJs), which behave as non-linear inductors, are currently the leading source of nonlinearity for superconducting circuits. Phase-slip junctions, which act as non-linear capacitors, are an alternative source of nonlinearity. Phase-slip junctions are fabricated from highly disordered superconductors with larger energy gaps than Al. Such junctions thus not only expand the class of possible superconducting circuits but also promise higher temperature and frequency operation. Here, we demonstrate the control and readout of a flux-based superconducting qubit. The qubit is composed of a phase slip junction and an inductance made from titanium nitride. We operate the qubit at zero flux, where its frequency is approximately 17 GHz. We measure an energy relaxation time, T₁ > 60μs and a Ramsey dephasing time, T_2R ≈ 17 ns. Finally, we demonstrate operation of the qubit at temperatures exceeding 300 mK and consider the relaxation and decoherence mechanisms of our phase-slip qubit.