标题： 基于量子点的相干自旋-光子接口中的测量诱导反作用 显示英文标题

标题： Measurement-induced back-action in a QD-based coherent spin-photon interface

摘要： 极化编码的自旋-光子接口是发展用于光子接收器的静态节点的有前途的候选方案，用于量子通信和分布式量子计算。 在这里，我们引入了一种时间分辨层析成像方法，该方法允许观察半导体量子点中的电子自旋动力学，并将其映射到反射光子的偏振态的动力学。 通过一次层析成像实验，我们可以推断出所有相关的自旋动力学时间尺度，包括进动、退相干和弛豫时间。 我们还演示并量化了由检测单个反射光子引起的对嵌入式自旋量子比特的测量反作用。 我们表明，通过选择测量的偏振基，可以调节所诱导的自旋态的激发态和相干性。 对嵌入式自旋量子比特的光子诱导反作用的控制构成了将自旋-光子接口用作量子接收器的关键要求。 显示英文摘要

摘要： Polarization-encoded spin-photon interfaces constitute promising candidates for the development of stationary nodes used as photon receivers, for quantum communication and distributed quantum computing. Here we introduce a time-resolved tomography approach which allows observing the dynamics of an electron spin, in a semiconductor quantum dot, mapped onto the dynamics of the polarization state of reflected photons. Through a single tomography experiment, we infer all the relevant spin dynamics timescales, including precession, decoherence and relaxation times. We also demonstrate and quantify the measurement back-action induced, on the embedded spin qubit, by the detection of a single reflected photon. We show that the induced population and coherence of the spin state can be tuned by the chosen polarization basis of the measurement. The control of the photon-induced back-action on the embedded spin qubit constitutes a crucial requirement for the use of spin-photon interfaces as quantum receivers.