论文标题
透射电离的动力学
Dynamics of Transmon Ionization
论文作者
论文摘要
电路QED中的量子测量和控制依赖于微波驱动器，其驱动幅度更高，理想情况下会导致更快的过程。然而，即使在适度的驱动振幅下，也观察到量子相干时间和读数保真度的降解，这些振幅与几个填充测量谐振器的光子相对应。在这里，我们从数值探索了强且几乎具有共振的测量驱动器下驱动的转基因系统的动力学，并找到了Transmon离子化的明确特征，其中Qubit逃脱了其余弦电位。使用半经典模型，我们将这种电离解释为在特定的共振光子群体下发生的共振产生的。我们发现，发生这些伪造过渡的光子种群是强烈的参数依赖性，并且可以在低谐振器光子种群下发生，这可以解释实验观察到的测量保真度中的降解。
Qubit measurement and control in circuit QED rely on microwave drives, with higher drive amplitudes ideally leading to faster processes. However, degradation in qubit coherence time and readout fidelity has been observed even under moderate drive amplitudes corresponding to few photons populating the measurement resonator. Here, we numerically explore the dynamics of a driven transmon-resonator system under strong and nearly resonant measurement drives, and find clear signatures of transmon ionization where the qubit escapes out of its cosine potential. Using a semiclassical model, we interpret this ionization as resulting from resonances occurring at specific resonator photon populations. We find that the photon populations at which these spurious transitions occur are strongly parameter dependent and that they can occur at low resonator photon population, something which may explain the experimentally observed degradation in measurement fidelity.
