Xie Xin, Li Qiuyang, Liu Chenxi, Liu Yuze, Lee Chulwon, Sun Kai, Deng Hui
Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA.
Michigan Institute for Data & AI in Society, University of Michigan, Ann Arbor, MI 48109, USA.
Sci Adv. 2025 May 23;11(21):eads0231. doi: 10.1126/sciadv.ads0231. Epub 2025 May 21.
Transport of elementary excitations is a fundamental property of two-dimensional (2D) semiconductors, essential for wide-ranging phenomena and device applications. Although exciton transport reported in 2D materials barely exceeds 1 to 2 micrometers, coherent coupling of excitons with photons to form polaritons enables extended transport lengths and offers opportunities to use photonic mode engineering for tailored transport. Conventional vertical cavity or waveguide polaritons, however, are challenging to tune and integrate into photonic circuits. We report the transport of transition metal dichalcogenide polaritons in 2D photonic crystals that are highly versatile for tuning, mode engineering, and integration. We achieve an order-of-magnitude enhancement in transport length compared to bare excitons and reveal transport dependence on polariton dispersion and population dynamics, which are controlled via photonic crystal design and pump intensity. Stimulated relaxation observed in the system suggests the potential for forming superfluid polaritons with frictionless transport. These findings establish 2D photonic crystal polaritons as a versatile platform for advancing photonic energy transport technologies.
元激发的输运是二维（2D）半导体的一项基本特性，对于广泛的现象和器件应用至关重要。尽管二维材料中报道的激子输运几乎不超过1至2微米，但激子与光子的相干耦合形成极化激元能够实现更长的输运长度，并为利用光子模式工程实现定制输运提供了机会。然而，传统的垂直腔或波导极化激元在调谐和集成到光子电路方面具有挑战性。我们报道了过渡金属二硫属化物极化激元在二维光子晶体中的输运，这种光子晶体在调谐、模式工程和集成方面具有高度的通用性。与裸激子相比，我们实现了输运长度一个数量级的增强，并揭示了输运对极化激元色散和布居动力学的依赖性，这可通过光子晶体设计和泵浦强度来控制。在该系统中观察到的受激弛豫表明形成具有无摩擦输运的超流极化激元的潜力。这些发现确立了二维光子晶体极化激元作为推进光子能量输运技术的通用平台。
