- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Anisotropic Flow Control and Gate Modulation of Hybrid Phonon-Polaritons
摘要： Light-matter interaction in two-dimensional photonic materials allows for confinement and manipulation of free-space radiation in sub-wavelength scales. Most notably, the van der Waals heterostructure comprising graphene (G) and hexagonal Boron Nitride (hBN) provides for gate-tunable hybrid hyperbolic plasmon phonon-polaritons (HP3). Here, we present anisotropic flow control and gate voltage modulation of HP3 modes in G-hBN lying on air-Au microstructured substrate. Using broadband infrared synchrotron radiation coupled to a scattering-type near-field optical microscope, we launch HP3 waves in both hBN Reststrahlen bands and observe directional propagation across in-plane heterointerfaces created at the air-Au junction. HP3 hybridization is modulated by varying the gate voltage between graphene and Au. In this case, we induce modifications to the coupling of continuum graphene plasmons with the discrete hBN hyperbolic phonon polaritons, which is interpreted as an extended Fano model. This is the first demonstration of control of polariton propagation, including a theoretical approach for a break of the reflection/transmission symmetry for HP3 modes. Our findings augment the degree of control of polaritons in G-hBN and related hyperbolic metamaterial nanostructures bringing novel insights to on-chip nano-optics communication and computing.
关键词： polaritonics,nano-photonics,graphene/boron nitride,near-field optics,hybrid polaritons,synchrotron infrared
更新于2025-09-19 17:15:36
-
Synchrotron infrared nanospectroscopy on a graphene chip
摘要： A recurring goal in biology and biomedicine research is to access the biochemistry of biological processes in liquids that represent the environmental conditions of living organisms. These demands are becoming even more specific as microscopy techniques are fast evolving to the era of single cells analysis. In the modality of chemical probes, synchrotron infrared spectroscopy (μ-FTIR) is a technique that is extremely sensitive to vibrational response of materials, however, the classical optical limits prevent the technique to access the biochemistry of specimens in the subcellular level. In addition, due to the intricate environmental requirements and strong infrared absorption of water, μ-FTIR of bioprocess in liquids remains highly challenging. In phase with those challenges, on-chip liquid cells emerge as a versatile alternative to control the water thickness while providing a biocompatible chemical environment for analytical analyzes. In this work we report the development of a liquid platform specially designed for nanoscale infrared analysis of biomaterials in wet environments. A key advantage of our designed platform is the use of graphene as the optical window that interfaces wet and dry environments in the liquid cell. By combining near-field optical microscopy and synchrotron infrared radiation, we measure nanoscale fingerprint IR absorbance of a variety of liquids often used in biological studies. Further, we demonstrate the feasibility of the platform for the chemical analysis of protein clusters immersed in water with a clear view of the proteins secondary structure signatures. The simplicity of the proposed platform combined to the high quality of our data make our findings a template for future microfluidic devices targeting dynamical nanoscale-resolved chemical analysis.
关键词： nanoscale chemical analysis,biomaterials,synchrotron infrared nanospectroscopy,graphene chip,liquid cell
更新于2025-09-11 14:15:04