Control over light propagation and localization in photonic crystals offers wide applications ranging from sensing and on-chip routing to lasing and quantum light–matter interfaces. Although in electronic crystals, magnetic fields can be used to induce a multitude of unique phenomena, the uncharged nature of photons necessitates alternative approaches to bring about similar control over photons at the nanoscale. Here we experimentally realize pseudomagnetic fields in two-dimensional photonic crystals through engineered strain of the lattice. Analogous to strained graphene, this induces flat-band Landau levels at discrete energies. We study the spatial and spectral properties of these states in silicon photonic crystals at telecom wavelengths with far-field spectroscopy. Moreover, taking advantage of the photonic crystal’s design freedom, we realize domains of opposite pseudomagnetic field and observe chiral edge states at their interface. We reveal that the strain-induced states can achieve remarkably high quality factors despite being phase matched to the radiation continuum. Together with the high density of states and high degeneracy associated with flat bands, this provides powerful prospects for enhancing light–matter interactions, and illustrates the broad potential of psdeudomagnetic fields in the nanophotonic domain. This work, thus, establishes a new design principle to govern both on-chip and radiating light fields.

光子晶体中光传播和定位的控制提供了广泛的应用，从传感和片上路由到激光和量子光物质界面。尽管在电子晶体中，磁场可用于引发多种独特的现象，但光子的不带电性质需要采用替代方法来在纳米尺度上对光子进行类似的控制。在这里，我们通过晶格的工程应变实验实现了二维光子晶体中的赝磁场。与应变石墨烯类似，这会在离散能量下产生平带朗道能级。我们利用远场光谱研究电信波长下硅光子晶体中这些状态的空间和光谱特性。此外，利用光子晶体的设计自由度，我们实现了相反的赝磁场域并观察了其界面处的手性边缘态。我们发现，尽管应变诱导态与辐射连续体相位匹配，但仍可以实现非常高的品质因数。加上与平带相关的高态密度和高简并性，这为增强光与物质相互作用提供了强大的前景，并说明了赝磁场在纳米光子领域的广泛潜力。因此，这项工作建立了一种新的设计原则来管理片上光场和辐射光场。