Characterization of High-Dimensional Entangled Systems via Mutually Unbiased Measurements
Characterization of High-Dimensional Entangled Systems via Mutually Unbiased Measurements
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DOI：
10.1103/physrevlett.110.143601
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发表时间：
2013-04-02
影响因子：
8.6
通讯作者：
Padgett, M. J.
中科院分区：
文献类型：
--
作者：
Giovannini, D.;Romero, J.;Padgett, M. J.
互无偏基（mub）在量子科学的许多协议中起着关键作用，例如量子密钥分发。然而，为任意高维系统定义mub在理论上是困难的，并且在这样的基础上进行测量可能很难实现。我们通过实验证明，仅考虑单个部分的mub就可以实现高维多部量子系统的有效量子态重建。单个子系统的状态空间总是小于组合系统的状态空间。因此，这种方法的好处是mub需要为子系统的小Hilbert空间定义，而不是为整个系统的大空间定义。当整个系统的mub的定义或度量具有挑战性时，这一点变得尤为重要。我们通过对一个由两个纠缠在轨道角动量自由度中的光子组成的高维系统进行测量来说明这种方法，并重建了该系统中单个光子从d = 2到5的状态。DOI: 10.1103 / PhysRevLett.110.143601
Mutually unbiased bases (MUBs) play a key role in many protocols in quantum science, such as quantum key distribution. However, defining MUBs for arbitrary high-dimensional systems is theoretically difficult, and measurements in such bases can be hard to implement. We show experimentally that efficient quantum state reconstruction of a high-dimensional multipartite quantum system can be performed by considering only the MUBs of the individual parts. The state spaces of the individual subsystems are always smaller than the state space of the composite system. Thus, the benefit of this method is that MUBs need to be defined for the small Hilbert spaces of the subsystems rather than for the large space of the overall system. This becomes especially relevant where the definition or measurement of MUBs for the overall system is challenging. We illustrate this approach by implementing measurements for a high-dimensional system consisting of two photons entangled in the orbital angular momentum degree of freedom, and we reconstruct the state of this system for dimensions of the individual photons from d = 2 to 5. DOI: 10.1103/PhysRevLett.110.143601