论文标题
量子 - 路由器：在光子水平上存储和重定向光
Quantum-router: Storing and redirecting light at the photon level
论文作者
论文摘要
我们提出了一种通过纯粹的电子均值（即不使用机械设备（例如微型摩尔阵列）），在连贯状态下在连贯状态下以空间重新穿线的单光子或光线的方法。该方法基于将传入光的量子状态映射到原子集合中的自旋波上，就像在光的量子记忆中所做的那样。然后，由施加的磁场梯度以控制的方式修饰自旋波的波形。最后，通过重新应用与存储相同的控制梁，信号脉冲以新的方向释放，取决于自旋波的偏转波形。我们通过数值模拟显示，对于平面中的任意偏转角，可以达到与简单的光子存储和向前方向重新排放相当的效率，并提出了一种新方法，以消除将存储动量作为量子内存中的变形源。在合理的参数制度中，根据偏转角度的不同，应在很少至$ \ sim100 $微秒的订单上以时间尺度来实现重新路由。可以使用Zeeman效应来实现的波形的移动，否则可以对自旋波进行最小的变化，也可以用于补充现有的AC-Stark Spin-Wave操纵方法。
We propose a method for spatially re-routing single photons or light in a coherent state with small average photon number by purely electronic means, i.e. without using mechanical devices such as micro-mirror arrays. The method is based on mapping the quantum state of the incoming light onto a spin-wave in an atomic ensemble as is done in quantum memories of light. Then the wavevector of the spin-wave is modified in a controlled way by an applied magnetic field gradient. Finally, by re-applying the same control beam as for storing, the signal pulse is released in a new direction that depends on the deflected wavevector of the spin-wave. We show by numerical simulation that efficiencies can be achieved for arbitrary deflection angles in the plane that are comparable with simple photon storage and re-emission in forward direction, and propose a new method for eliminating the stored momentum as source of decoherence in the quantum memory. In a reasonable parameter regime, the re-routing should be achievable on a time-scale on the order of few to $\sim100$ microseconds, depending on the deflection angle. The shifts in the wavevector that can be achieved using the Zeeman-effect, with otherwise minimal changes to the spin-wave, can also be used to complement existing ac-Stark spin-wave manipulation methods.
