Superconducting circuits host two-level systems with lifetimes exceeding one second
Researchers used wide-band quantum-jump correlation spectroscopy on flux-tunable transmon qubits to find microscopic two-level systems (TLSs) that last much longer than expected, exceeding one second. These long-lived TLSs cause correlated dynamics in the qubit, which has implications for quantum error correction. The findings show that standard tunneling defects can account for these long lifetimes, suggesting these TLSs could be used as quantum memory.