Enhancing the coherence of superconducting qubits with electric fields

Superconducting qubits are severely hampered by decoherence, of which a major part originates from tunneling defects at qubit circuit interfaces.

Here we show that qubit coherence can be improved by tuning dominating defects away from the qubit resonance. In our experiments, such defects are tuned by exposing the qubit sample to a DC-electric field. Using a simple algorithm to optimize the applied electric field bias, we found that the average T₁-time of a transmon qubit could be enhanced by 23%.

This technique can also be implemented in superconducting quantum processors to enable simultaneous coherence optimization of all qubits.