论文标题
在Transmon Qubit的高级拉姆西曲线中的噪声特异性节拍
Noise-specific beats in the higher-level Ramsey curves of a transmon qubit
论文作者
论文摘要
在较高水平的超导式透射设备以及更普遍的敏感设备中，$ T_2^*$测量值在存在低频时间相关的$ 1/f $电荷噪声和准粒子引起的平等倾斜的情况下可以使总降低时间低估。电荷变化表现为在几个Ramsey条纹曲线的覆盖层中观察到的跳动模式，并使用现象学Ramsey曲线模型复制，该模型解释了电荷变化。 $ t_2^*$ dephasing时间更准确地表示总的dephasing时间。将现象学模型与Lindblad Master方程模型进行了比较。发现这两种模型彼此一致和实验数据。最后，现象学配方实现了一种简单的方法，其中低频噪声的功率谱密度（PSD）可以从几个拉姆齐曲线的覆盖层中推断出来。
In the higher levels of superconducting transmon devices, and more generally charge sensitive devices, $T_2^*$ measurements made in the presence of low-frequency time-correlated $1/f$ charge noise and quasiparticle-induced parity flips can give an underestimation of the total dephasing time. The charge variations manifest as beating patterns observed in the overlay of several Ramsey fringe curves, and are reproduced with a phenomenological Ramsey curve model which accounts for the charge variations. $T_2^*$ dephasing times which more accurately represent the total dephasing time are obtained. The phenomenological model is compared with a Lindblad master equation model. Both models are found to be in agreement with one another and the experimental data. Finally, the phenomenological formulation enables a simple method in which the power spectral density (PSD) for the low-frequency noise can be inferred from the overlay of several Ramsey curves.
