Single-photon entanglement generation by wavefront shaping in a multiple-scattering medium

Pump-shaping of non-collinear and non-degenerate entangled photons

Free-space quantum key distribution is gaining increasing interest as a leading platform for long range quantum communication. However, the sensitivity of quantum correlations to scattering induced by turbulent atmospheric links limits the performance of such systems. Recently, methods for compensating the scattering of entangled photons have been demonstrated, allowing for real-time optimization of their quantum correlations. In this Letter, we demonstrate the use of wavefront shaping for compensating the scattering of non-collinear and non-degenerate entangled photons. These results demonstr…

Modulating quantum fluctuations of scattered lights in disordered media via wavefront shaping

After multiple scattering of quadrature-squeezed lights in a disordered medium, the quadrature amplitudes of the scattered modes present an excess noise above the shot-noise level [Opt. Expr. 14, 6919 (2006)]. A natural question is raised whether there exists a method of suppressing the quadrature fluctuation of the output mode. The answer is affirmative. In this work, we prove that wavefront shaping is a promising method to reduce the quantum noise of quadrature amplitudes of the scattered modes. This reduction is owing to the destructive interference of quantum noise. Specifically, when the …

使用前导波信标通过厚散射介质整形纠缠光子

Shaping entangled photons through thick scattering media using an advanced wave beacon

提出受 Klyshko 前导波图像启发的新反馈机制，通过反向传播的经典激光束实现厚散射介质中的纠缠光子波前整形，为量子波前整形的实际应用提供了鲁棒且免对准的方案。

Quantum Reference Beacon-Guided Super-Resolution Optical Focusing in Complex Media

Optical random scattering is generally considered to be a nuisance of microscopy that limits imaging depth and spatial resolution. Wavefront shaping techniques have recently enabled optical imaging at unprecedented depth, but a remaining problem is also to attain super-resolution within complex media. To address this challenge, we introduce a new technique to focus inside of complex media by the use of a quantum reference beacon (QRB), consisting of solid-state quantum emitters with spin-dependent fluorescence. This QRB provides subwavelength guidestar feedback for wavefront shaping to achieve…

通过相干-纠缠转移实现高维双光子态的波前校正

Wavefront correction of high-dimensional two-photon states via coherence-entanglement transfer

针对量子态传输受环境像差散射干扰、经典信标校正方案装置开销大且匹配难度高的问题，提出利用泵浦整形调控双光子态纠缠度，通过其经典相干模式测量信道传输矩阵并校正畸变，实现高维纠缠态低误差传输。

Spatial entanglement engineering by pump shaping

The ability to engineer the properties of quantum optical states is essential for quantum information processing applications. Here, we demonstrate tunable control of spatial correlations between photon pairs produced by spontaneous parametric down-conversion. By shaping the spatial pump beam profile in a type-I collinear configuration, we tailor the spatial structure of coincidences between photon pairs entangled in high dimensions, without effect on intensity. The results highlight fundamental aspects of spatial coherence and hold potential for the development of quantum technologies based o…

Real-time shaping of entangled photons by classical control and feedback

Quantum technologies hold great promise for revolutionizing photonic applications such as cryptography. Yet their implementation in real-world scenarios is held back, mostly due to sensitivity of quantum light to scattering. Recent developments in optimizing the shape of single photons introduce new ways to control quantum light. Nevertheless, shaping single photons in real-time remains a challenge due to the weak associated signals, which are too noisy for optimization processes. Here, we overcome this challenge and control scattering of entangled photons by shaping the classical laser beam t…

两个光子通过分束器的波包干涉：从时间纠缠到波包整形

Wavepacket interference of two photons through a beam splitter: from temporal entanglement to wavepacket shaping

解析研究两不同时间形状光子通过分束器的干涉，提出时间纠缠与光子整形应用，发现50/50分束器可生成时间模式编码Bell态，且探测一光子能以超99%保真度将另一光子整形为高斯波包，有望解决光量子网络形状失配。

使用对称化优化实现空间纠缠光子的快速高效波前校正

Rapid and efficient wavefront correction for spatially entangled photons using symmetrized optimization

提出对称化遗传算法（sGA）用于空间纠缠光子的自适应波前校正，利用偶宇称分量影响双光子相关性的洞见将参数空间减半，实现比标准遗传算法更快的收敛与更高的增强效果，从而有效校正复杂介质中的纠缠退化。

Heralded temporal shaping of single photons enabled by entanglement

We propose a method to produce pure single photons with an arbitrary designed temporal shape in a heralded, lossless and scalable way. As the indispensable resource, the method uses pairs of time-energy entangled photons. To accomplish the shaping, one photon of a pair undergoes temporal modulation according to the desired shape. Subsequent frequency-resolving detection of the photon heralds its entangled counterpart in a pure quantum state with a temporal shape non-locally affected by the modulation. We found conditions for the shape of the heralded photon to reproduce the modulation function…

Shaping contours of entanglement islands in BCFT

In this paper, we study the fine structure of entanglement in holographic two-dimensional boundary conformal field theories (BCFT) in terms of the spatially resolved quasilocal extension of entanglement entropy - entanglement contour. We find that the boundary induces discontinuities in the contour revealing hidden localization-delocalization patterns of entanglement degrees of freedom. Moreover, we observe the formation of ``islands'' where the entanglement contour vanishes identically implying that these regions do not contribute to the entanglement at all. We argue that these phenomena are …

Manipulation and certification of high-dimensional entanglement through a scattering medium

High-dimensional entangled quantum states improve the performance of quantum technologies compared to qubit-based approaches. In particular, they enable quantum communications with higher information capacities or enhanced imaging protocols. However, the presence of optical disorder such as atmospheric turbulence or biological tissue perturb quantum state propagation and hinder their practical use. Here, we demonstrate a wavefront shaping approach to transmit high-dimensional spatially entangled photon pairs through scattering media. Using a transmission matrix approach, we perform wavefront c…

预通道纠缠塑造在几何熵视角下超越后分馏

Pre-Channel Entanglement Shaping Achieves Fundamental Superiority over Post-Distillation: A Geometric Entropy Perspective

本文从几何熵视角出发，提出预通道纠缠塑造（PES）方法，通过主动设计系统-环境耦合，在通道传输前或期间实现比后分馏协议更高效的纯化能力，并通过量子相对熵与分离态框架证明其物理不可行性。