High-harmonic generation has been driving the development of attosecond science and sources. More recently, high-harmonic generation in solids has been adopted by other communities as a method to study material properties. However, so far high-harmonic generation has only been driven by classical light, despite theoretical proposals to do so with quantum states of light. Here we observe non-perturbative high-harmonic generation in solids driven by a macroscopic quantum state of light, a bright squeezed vacuum, which we generate in a single spatiotemporal mode. The process driven by a bright squeezed vacuum is considerably more efficient in the generation of high harmonics than classical light of the same mean intensity. Due to its broad photon-number distribution, covering states from 0 to 2 × 10¹³ photons per pulse, and strong subcycle electric field fluctuations, a bright squeezed vacuum gives access to free carrier dynamics within a much broader range of peak intensities than accessible with classical light.

高谐波产生一直在推动阿秒科学和源的发展。最近，固体中的高谐波生成已被其他社区用作研究材料特性的一种方法。然而，到目前为止，高谐波的产生仅由经典光驱动，尽管理论上提出了对光的量子态进行驱动。在这里，我们观察到由光的宏观量子态（明亮的挤压真空）驱动的固体中的非扰动高谐波产生，我们在单一时空模式下产生。由明亮挤压真空驱动的过程在产生高谐波方面比相同平均强度的经典光要高效得多。由于其宽光子数分布，覆盖从每脉冲 0 到 2 × 10¹³ 个光子的状态，以及强大的子周期电场波动，明亮的挤压真空可以在比传统光更广泛的峰值强度范围内获得自由载流子动力学。