Amorphous dielectric materials have been known to host two-level systems (TLSs) for more than four decades. Recent developments on superconducting resonators and qubits enable detailed studies on the physics of TLSs. In particular, measuring the loss of a device over long time periods (a few days) allows us to investigate stochastic fluctuations due to the interaction between TLSs. We measure the energy relaxation time of a frequency-tunable planar superconducting qubit over time and frequency. The experiments show a variety of stochastic patterns that we are able to explain by means of extensive simulations. The model used in our simulations assumes a qubit interacting with high-frequency TLSs, which, in turn, interact with thermally activated low-frequency TLSs. Our simulations match the experiments and suggest the density of low-frequency TLSs is about three orders of magnitude larger than that of high-frequency ones.

中文翻译：

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相互作用的缺陷在超导量子位中产生随机波动

众所周知，非晶介电材料可以承载两级系统 (TLS) 已有四十多年的历史。超导谐振器和量子位的最新发展使得对 TLS 物理的详细研究成为可能。特别是，在长时间（几天）内测量设备的损耗使我们能够调查由于 TLS 之间的相互作用引起的随机波动。我们测量频率可调平面超导量子位随时间和频率的能量弛豫时间。实验显示了我们能够通过广泛的模拟来解释的各种随机模式。我们模拟中使用的模型假设量子位与高频 TLS 相互作用，而高频 TLS 又与热激活的低频 TLS 相互作用。