标题： 使用自旋轨道纠缠的单自旋测量 显示英文标题

标题： Single spin measurement using spin-orbital entanglement

摘要： 单个自旋测量是基于自旋的量子计算中的一个重大挑战。 在本文中，我们提出了一种新的方法来测量限制在量子点（QD）中的单个电子的自旋。 我们的策略是通过使用单位门将自旋和轨道自由度纠缠起来。 一个由第二个空量子点定义的{\em 轨道量子比特}用作辅助比特，并被准备在一个已知的初始状态中。 测量轨道量子比特将揭示（未知的）初始自旋量子比特的状态，从而将问题简化为更简单的单电荷测量任务。 由于自旋-电荷转换是以单位概率进行的，原则上可以实现电子自旋的单次测量。 我们评估了该方法对各种误差源的鲁棒性，并简要讨论了可能的实现方式。 显示英文摘要

摘要： Single spin measurement represents a major challenge for spin-based quantum computation. In this article we propose a new method for measuring the spin of a single electron confined in a quantum dot (QD). Our strategy is based on entangling (using unitary gates) the spin and orbital degrees of freedom. An {\em orbital qubit}, defined by a second, empty QD, is used as an ancilla and is prepared in a known initial state. Measuring the orbital qubit will reveal the state of the (unknown) initial spin qubit, hence reducing the problem to the easier task of single charge measurement. Since spin-charge conversion is done with unit probability, single-shot measurement of an electronic spin can be, in principle, achieved. We evaluate the robustness of our method against various sources of error and discuss briefly possible implementations.