近日，粤港澳大湾区量子科学中心（广东）Yu-Wei Lu团队报道了通过微腔的手性异常点实现可调谐的相干和耗散光物质相互作用。2025年12月11日，《物理评论A》杂志发表了这一成果。

利用现实量子系统中泛在粒子耗散的能力为发展先进的量子技术提供了巨大的前景。特别是，耗散的存在违反了厄米性的基本前提，并导致了参数空间中与聚并特征态相关的非厄米奇点，即异常点（EPs），为在动态演化和稳态极限下操纵量子态提供了一种新的策略。

研究组证明了对于支持手性EPs的微腔，通过调整复杂耦合率的相位因子，可以灵活地将腔光子和量子发射器之间的光-物质相互作用从相干切换到完全耗散，这是微腔的手性EPs提供的额外自由度。可调的相干和耗散光-物质相互作用由量子动力学和光谱特征证明，其中耦合量子系统的色散从能级排斥转变为能级吸引。虽然耗散通常被认为对量子效应是致命的，应该被抑制，但在这里研究组发现，通过非厄米光子封锁，在弱耦合状态下通过非厄米光子封锁实现高效的单光子发射显示出独特的优势，这源于损失的非调和性，而不是传统光子封锁（CPB）的特征能级。

在相干光-物质相互作用中，与CPB相比，光子相关性和强度都有了5个数量级以上的巨大提高。研究组期望他们的工作能够丰富对开放光子谐振腔中光-物质相互作用的理解，并通过利用电磁环境的非hermicity，为各种量子系统中的量子态和量子相关性的操纵提供见解。

附：英文原文

Title: Tunable coherent and dissipative light-matter interactions enabled by chiral exceptional points of a microcavity

Author: Yu-Wei Lu

Issue&Volume: 2025/12/11

Abstract: The ability to harness the ubiquitous dissipation in realistic quantum systems holds great promise for developing advanced quantum technologies. In particular, the presence of dissipation violates the fundamental premise of Hermiticity and results in the non-Hermitian singularities associated with coalesced eigenstates in parameter space known as exceptional points (EPs), providing a new strategy to manipulate quantum states in both dynamical evolution and stationary limit. In this work, we show that for a microcavity supporting chiral EPs, light-matter interaction between the cavity photons and a quantum emitter can be flexibly switched from coherent to fully dissipative by tuning the phase factor of a complex coupling rate, an additional degree of freedom offered by the chiral EPs of a microcavity. The tunable coherent and dissipative light-matter interactions are evidenced by the distinguishing quantum dynamics and optical spectra, where the dispersion of a coupled quantum system changes from level repulsion to level attraction. While dissipation is generally considered fatal for quantum effects and should be suppressed, here we find that the EP-enabled dissipative light-matter interaction shows a unique advantage in achieving high-efficiency single-photon emission in a weak-coupling regime through the non-Hermitian photon blockade, which originates from the anharmonicity in the losses instead of in the eigenenergy levels for the conventional photon blockade (CPB). A giant enhancement of more than 5 orders of magnitude is found for both photon correlations and intensity compared to that of CPB in coherent light-matter interaction. We expect our work to enrich the understanding of light-matter interaction in open photonic resonators and provide insight into the manipulation of quantum states and quantum correlations in a wide variety of quantum systems by utilizing the non-Hermicity of electromagnetic environments.

DOI: 10.1103/rp38-t5cn

Source: https://journals.aps.org/pra/abstract/10.1103/rp38-t5cn