论文标题
引力波动如何降低高维空间纠缠
How gravitational fluctuations degrade the high-dimensional spatial entanglement
论文作者
论文摘要
带有轨道角动量（OAM）的扭曲光子是未来星际通信的合格候选者。但是，在时空中，引力波动无处不在。因此，关于重力波动如何影响扭曲光子跨越弯曲的时空质地时，引力波动如何影响高维的OAM纠缠的一致性和程度，因此自然而然地出现了一个基本问题。在这里，我们考虑了与高斯分布波动的协变量标量Helmholtz方程和Minkowski指标，并通过分析地进行了表述，描述了Laguerre-Gaussian模式空间中扭曲光的运动。可以看出，在引力波动的存在下，绿色的体育不能保持保守。此外，将两光子密度矩阵得出以用于星际OAM量子纠缠分布，并且纠缠降解程度的特征是纯度和负性。据揭示，较高的OAM纠缠更容易受到时空波动的影响。我们认为，我们的发现对于未来与扭曲光子的星际量子通信至关重要。
Twisted photons carrying orbital angular momentum (OAM) are competent candidates for future interstellar communications. However, the gravitational fluctuations are ubiquitous in spacetime. Thus a fundamental question arises naturally as to how the gravitational fluctuations affect the coherence and the degree of high-dimensional OAM entanglement when twisted photons travel across the textures of curved spacetime. Here, we consider the covariant scalar Helmholtz equations and the Minkowski metric with fluctuations of Gaussian distribution and formulate analytically the equations describing the motion for twisted light in the Laguerre-Gaussian mode space. It is seen that the OAM cannot remain conserved in the presence of gravitational fluctuations. Furthermore, two-photon density matrices are derived for interstellar OAM quantum entanglement distribution, and the degree of entanglement degradation is characterized by purity and negativity. It is revealed that the higher-dimensional OAM entanglement is more susceptible to spacetime fluctuations. We believe that our findings will be of fundamental importance for the future interstellar quantum communications with twisted photons.
