论文标题
由于背景电离辐射而导致超导零件中的TLS动力学
TLS Dynamics in a Superconducting Qubit Due to Background Ionizing Radiation
论文作者
论文摘要
超导量子的寿命必须长而稳定，才能为量子计算提供足够的基础。两级系统（TLSS）当前是一种主要的损耗机制，这种稳定性损害了较慢的光谱动力学，从而破坏了小时的时间尺度上的量子寿命。在毫秒的时间尺度上，稳定性也受到威胁，最近发现电离辐射会导致相关的多量衰变爆发，从而使量子误差校正复杂化。在这里，我们研究了27 Quit的处理器上的电离辐射和TLS动力学，将标准的Transmon量子台重新利用为辐射影响和TLS动力学的传感器。与先前的文献不同，我们观察到量子寿命对辐射的影响产生的瞬态准颗粒的弹性。但是，我们还观察到这两个过程之间的新相互作用“ TLS争夺”，其中辐射影响会导致多个TLS的频率跃升，我们建议这是由于在辐射撞击附近被量子的旋翼表所示的相同电荷重排。随着TLS争夺将TLSS带出或与量子共鸣，量子的寿命会增加或减少。因此，我们的发现将辐射确定为对量子寿命中波动的新贡献，这对努力表征和改善设备稳定性的努力
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. Unlike prior literature, we observe resilience of the qubit lifetimes to the transient quasiparticles generated by the impact of radiation. However, we also observe a new interaction between these two processes, "TLS scrambling," in which a radiation impact causes multiple TLSs to jump in frequency, which we suggest is due to the same charge rearrangement sensed by qubits near a radiation impact. As TLS scrambling brings TLSs out of or in to resonance with the qubit, the lifetime of the qubit increases or decreases. Our findings thus identify radiation as a new contribution to fluctuations in qubit lifetimes, with implications for efforts to characterize and improve device stability
