Dynamical regimes of a quantum SWAP gate beyond the Fermi golden rule
Dynamical regimes of a quantum SWAP gate beyond the Fermi golden rule
复制标题
DOI：
10.1103/physreva.78.062116
复制
发表时间：
2008-12-01
影响因子：
2.9
通讯作者：
Pastawski, Horacio M.
中科院分区：
文献类型：
--
作者：
Dente, Axel D.;Bustos-Marun, Raul A.;Pastawski, Horacio M.
我们讨论了浴缸的记忆如何影响掉期门的动态。我们提出了一个精确可解的模型，当超越费米黄金法则处理时，该模型显示了各种动力学跃迁。通过连续移动单个参数，未受扰动的拉比频率，我们扫描了状态密度的不同解析性质：(I)在(Ii)两个可分辨的共振中的例外点处分裂的崩塌共振；(Iii)带外共振；(Iv)虚态；以及(V)纯点谱。我们将它们分别与不同的动力学机制联系在一起：过阻尼态、阻尼态、环境控制的量子扩散、反常扩散和局域动力学。交换门的频率取决于未受干扰的拉比频率。在区域I中根本没有振荡，而在区域III和IV中，振荡频率特别稳定，因为它由环境的带宽决定。反常扩散可以作为存在难以捉摸的虚态的标志。
We discuss how the bath's memory affects the dynamics of a SWAP gate. We present an exactly solvable model that shows various dynamical transitions when treated beyond the Fermi golden rule. By moving continuously a single parameter, the unperturbed Rabi frequency, we sweep through different analytic properties of the density of states: (I) collapsed resonances that split at an exceptional point in (II) two resolved resonances; (III) out-of-band resonances; (IV) virtual states; and (V) pure point spectrum. We associate them with distinctive dynamical regimes: overdamped, damped oscillations, environment controlled quantum diffusion, anomalous diffusion, and localized dynamics, respectively. The frequency of the SWAP gate depends differently on the unperturbed Rabi frequency. In region I there is no oscillation at all, while in the regions III and IV the oscillation frequency is particularly stable because it is determined by the environment's band width. The anomalous diffusion could be used as a signature for the presence of the elusive virtual states.