机械谐振子的量子跃迁

measurements. We fit the measured evolution of P(n=1) using this model with two free parameters: P(e|even), the probability of measuring e⟩ given an even phonon number, and α, the amplitude of the initial coherent state. The fit (gray region in Fig. 3) shows good agreement with the data, yielding α = 0.356 ± 0.087 and P(e|even) = 0.296 ± 0.037. We independently verify the fitted value of α using the data shown in Fig. 2B. From the relative peak areas corresponding to n = 0 and n = 1, we extract α = 0.283 ± 0.032. The dominant source of measurement infidelity is qubit decoherence during the Ramsey sequence. …