Information encoded in networks of stationary, interacting spin-1/2 particles is central for many applications ranging from quantum spintronics to quantum information processing. Without control, however, information transfer through such networks is generally inefficient. Currently available control methods to maximize the transfer fidelities and speeds mainly rely on dynamic control using time-varying fields and often assume instantaneous readout. We present an alternative approach to achieving efficient, high-fidelity transfer of excitations by shaping the energy landscape via the design of time-invariant feedback control laws without recourse to dynamic control. Both instantaneous readout and the more realistic case of finite readout windows are considered. The technique can also be used to freeze information by designing energy landscapes that achieve Anderson localization. Perfect state or superoptimal transfer and localization are enabled by conditions on the eigenstructure of the system and signature properties for the eigenvectors. Given the eigenstructure enabled by superoptimality, it is shown that feedback controllers that achieve perfect state transfer are, surprisingly, also the most robust with regard to uncertainties in the system and control parameters.

中文翻译：

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自旋电子网络信息传输反馈控制律的设计


在静止、相互作用的自旋 1/2 粒子网络中编码的信息是从量子自旋电子学到量子信息处理等许多应用的核心。然而，如果没有控制，通过此类网络的信息传输通常效率低下。目前可用的最大化传输保真度和速度的控制方法主要依赖于使用时变场的动态控制，并且通常假设瞬时读出。我们提出了一种替代方法，通过设计时不变反馈控制律来塑造能量景观，从而实现高效、高保真的激励传递，而不需要动态控制。考虑瞬时读出和有限读出窗口的更现实的情况。该技术还可以通过设计实现安德森定位的能量景观来冻结信息。完美状态或超优化传输和定位是通过系统特征结构的条件和特征向量的签名属性来实现的。令人惊讶的是，考虑到超最优性所实现的本征结构，实现完美状态转移的反馈控制器对于系统和控制参数的不确定性也是最鲁棒的。