标题： 异常光阻塞：利用手性 exceptional 点工程化光阻塞 显示英文标题

标题： Exceptional Photon Blockade: Engineering Photon Blockade with Chiral Exceptional Points

摘要： 非厄米谱退化，被称为例外点（EPs），表现为系统中特征值及其相关本征态的同时合并。 大量有趣的EP效应及其应用已在经典领域被揭示，例如损耗诱导的激光、单模激光和EP增强传感。 在这里我们展示了一种纯量子效应——单光子阻塞，在Kerr微环谐振器中由于光模式与非线性诱导的非简谐能级间隔之间由EP引起的不对称耦合而出现。 这种光子阻塞的一个显著特征是在双光子共振时出现，而在厄米系统中这只会导致光子诱导隧穿，但不会导致光子阻塞。 通过调节系统靠近或远离EP，可以控制量子关联，这意味着我们的系统有潜力用于频率可调的单光子生成以及抗聚束到聚束的光开关。 我们的工作为EP工程化的纯量子效应提供了新的见解，为制造和利用各种单光子量子EP设备提供了独特的机会。 显示英文摘要

摘要： Non-Hermitian spectral degeneracies, known as exceptional points (EPs), feature simultaneous coalescence of both eigenvalues and the associated eigenstates of a system. A host of intriguing EP effects and their applications have been revealed in the classical realm, such as loss-induced lasing, single-mode laser, and EP-enhanced sensing. Here we show that a purely quantum effect, known as single-photon blockade, emerges in a Kerr microring resonator due to EP-induced asymmetric coupling between the optical modes and the nonlinearity-induced anharmonic energy-level spacing. A striking feature of this photon blockade is that it emerges at two-photon resonance which in Hermitian systems will only lead to photon-induced tunneling but not to photon blockade. By tuning the system towards to or away from an EP, one can control quantum correlations, implying the potential use of our system for frequency tunable single-photon generation and an antibunching-to-bunching light switch. Our work sheds new light on EP-engineered purely quantum effects, providing unique opportunities for making and utilizing various single-photon quantum EP devices.