近日，德国马克斯·普朗克物质结构与动力学研究所McIver, James W.团队研究了范德华异质结构的腔电动力学。该研究于2025年10月20日发表在《自然—物理学》杂志上。
范德瓦尔斯异质结构中存在多种可调量子效应，这些效应可通过静电栅极进行原位调控。其构成的二维材料与栅极会自然形成等离激元自谐振腔，由于有限尺寸效应，可将光束缚在电流密度的驻波中。典型石墨栅极的等离激元共振频率覆盖吉赫至太赫波段，对应的微电子伏至毫电子伏能量尺度，与其电控的范德瓦尔斯异质结构物理现象能量尺度高度吻合。这表明石墨栅极的内建谐振腔模式可能影响这些异质结构的低能物理特性。
然而，由于器件尺寸显著小于相关波长的衍射极限，探测这类腔耦合电动力学面临挑战。研究组报道了栅压可调石墨烯异质结构的本征腔电导特性：通过调控载流子浓度，观测到石墨烯与石墨等离激元腔模式在超强耦合区域的耦合行为及光谱权重转移。研究组构建了解析模型阐释实验结果，并提出了谐振腔设计的通用原则。这些发现表明本征腔效应对于理解范德瓦尔斯异质结构的低能电动力学具有重要意义，同时为通过腔控实现功能化应用开辟了新路径。
附：英文原文
Title: Cavity electrodynamics of van der Waals heterostructures
Author: Kipp, Gunda, Bretscher, Hope M., Schulte, Benedikt, Herrmann, Dorothee, Kusyak, Kateryna, Day, Matthew W., Kesavan, Sivasruthi, Matsuyama, Toru, Li, Xinyu, Langner, Sara Maria, Hagelstein, Jesse, Sturm, Felix, Potts, Alexander M., Eckhardt, Christian J., Huang, Yunfei, Watanabe, Kenji, Taniguchi, Takashi, Rubio, Angel, Kennes, Dante M., Sentef, Michael A., Baudin, Emmanuel, Meier, Guido, Michael, Marios H., McIver, James W.
Issue&Volume: 2025-10-20
Abstract: Van der Waals heterostructures host many-body quantum phenomena that are tunable in situ using electrostatic gates. Their constituent two-dimensional materials and gates can naturally form plasmonic self-cavities, confining light in standing waves of current density due to finite-size effects. The plasmonic resonances of typical graphite gates fall in the gigahertz to terahertz range, corresponding to the same microelectronvolt to millielectronvolt energy scale as the phenomena in van der Waals heterostructures that they electrically control. This raises the possibility that the built-in cavity modes of graphite gates are relevant for shaping the low-energy physics of these heterostructures. However, probing these cavity-coupled electrodynamics is challenging as devices are notably smaller than the diffraction limit at the relevant wavelengths. Here we report on the intrinsic cavity conductivity of gate-tunable graphene heterostructures. As the carrier density is tuned, we observe coupling and spectral weight transfer between graphene and graphite plasmonic cavity modes in the ultrastrong coupling regime. We present an analytical model to describe the results and provide general principles for cavity design. Our findings show that intrinsic cavity effects are important for understanding the low-energy electrodynamics of van der Waals heterostructures and open a pathway for useful functionality through cavity control.
DOI: 10.1038/s41567-025-03064-8
Source: https://www.nature.com/articles/s41567-025-03064-8