TLS Dynamics in a Superconducting Qubit Due to Background Ionizing Radiation

Understand

Superconducting qubit lifetimes must be both long and stable to provide an adequate foundation for quantum computing.

• This stability is imperiled by two-level systems (TLSs), currently a dominant loss mechanism, which exhibit slow spectral dynamics that destabilize qubit lifetimes on hour timescales.
• Stability is also threatened at millisecond timescales, where ionizing radiation has recently been found to cause bursts of correlated multi-qubit decays, complicating quantum error correction.
• Here we study both ionizing radiation and TLS dynamics on a 27-qubit processor, repurposing the standard transmon qubits as sensors of both radiation impacts and TLS dynamics.