近日，美国哈佛大学Lobet, Michal团队研究了介电μ近零超材料中的长程量子纠缠。相关论文于2025年9月3日发表在《光：科学与应用》杂志上。

纠缠在量子信息处理中是至关重要的。许多量子系统在一个波长的距离上存在空间退相干，并且由于耗散而不能在短时间内保持。然而，芯片上量子信息处理的发展需要长期的解决方案。人们提出了介导量子比特与其环境相互作用的光子储层。近年来的研究利用近零折射率介质内波长的延长来解决量子发射体位置灵敏度较低的长程问题。然而，这些最近的提案主题是等离子体接近零的波导本质上是有损耗的。

研究组提出了一种与氮空位（NV）金刚石中心片上技术兼容的全介电平台，以大幅提高17个自由空间波长（约12.5 μm，使用μ接近零的超材料）。 他们评估了瞬态和稳态并发，与以前的工作相比，显示了一个数量级的增强。据他们所知，这是第一次采用这种策略报道这么远的距离。此外，零时延二阶相关函数g₁₂⁽²⁾(0)的值显示了与高度一致性相关的反聚束签名。

附：英文原文

Title: Long-range quantum entanglement in dielectric mu-near-zero metamaterials

Author: Mello, Olivia, Vertchenko, Larissa, Nelson, Seth, Debacq, Adrien, Guney, Durdu, Mazur, Eric, Lobet, Michal

Issue&Volume: 2025-09-03

Abstract: Entanglement is paramount in quantum information processing. Many quantum systems suffer from spatial decoherence in distances over a wavelength and cannot be sustained over short time periods due to dissipation. However, long range solutions are required for the development of quantum information processing on chip. Photonic reservoirs mediating the interactions between qubits and their environment are suggested. Recent research takes advantage of extended wavelength inside near-zero refractive index media to solve the long-range problem along with less sensitivity on the position of quantum emitters. However, those recent proposals use plasmonic epsilon near-zero waveguides that are intrinsically lossy. Here, we propose a fully dielectric platform, compatible with the Nitrogen Vacancy (NV) diamond centers on-chip technology, to drastically improve the range of entanglement over 17 free-space wavelengths, or approximatively 12.5μm, using mu near-zero metamaterials. We evaluate transient and steady state concurrence demonstrating an order of magnitude enhancement compared to previous works. This is, to the best of our knowledge, the first time that such a long distance is reported using this strategy. Moreover, value of the zero time delay second order correlation function {g}_{12}^{(2)}(0) are provided, showing antibunching signature correlated with a high degree of concurrence.

DOI: 10.1038/s41377-025-01994-9

Source: https://www.nature.com/articles/s41377-025-01994-9