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تسجيل مستخدم جديدLarge few-layer hexagonal boron nitride flakes for nonlinear optics
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Hexagonal boron nitride (hBN) is a layered dielectric material with a wide range of applications in optics and photonics. In this work, we demonstrate a fabrication method for few-layer hBN flakes with areas up to 5000 $rm mu m$. We show that hBN in this form can be integrated with photonic microstructures: as an example, we use a circular Bragg grating (CBG). The layer quality of the exfoliated hBN flake on a CBG is confirmed by second-harmonic generation (SHG) microscopy. We show that the SHG signal is uniform across the hBN sample outside the CBG and is amplified in the centre of the CBG.
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Two-dimensional hexagonal boron nitride offers intriguing opportunities for advanced studies of light-matter interaction at the nanoscale, specifically for realizations in quantum nanophotonics. Here, we demonstrate the engineering of optically-addre
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We demonstrate the fabrication of large-scale arrays of single photon emitters (SPEs) in hexagonal boron nitride (hBN). Bottom-up growth of hBN onto nanoscale arrays of dielectric pillars yields corresponding arrays of hBN emitters at the pillar site
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We report second-harmonic generation (SHG) from thick hexagonal boron nitride (hBN) flakes with approximately 109-111 layers. The resulting effective second-order susceptibility is similar to previously reported few-layer experiments. This confirms t
hat thick hBN flakes can serve as a platform for nonlinear optics, which is useful because thick flakes are easy to exfoliate while retaining a large flake size. We also show spatial second-harmonic maps revealing that SHG remains a useful tool for the characterization of the layer structure even in the case of a large number of layers.
Two-dimensional materials offer a versatile platform to study high-harmonic generation (HHG), encompassing as limiting cases bulk-like and atomic-like harmonic generation [Tancogne-Dejean and Rubio, Science Advance textbf{4}, eaao5207 (2018)]. Unders
tanding the high-harmonic response of few-layer semiconducting systems is important, and might open up possible technological applications. Using extensive first-principle calculations within a time-dependent density functional theory framework, we show how the in-plane and out-of-plane nonlinear non-perturbative response of two-dimensional materials evolve from the monolayer to the bulk. We illustrate this phenomenon for the case of multilayer hexagonal BN layered systems. Whereas the in-plane HHG is found not to be strongly altered by the stacking of the layers, we found that the out-of-plane response is strongly affected by the number of layers considered. This is explained by the interplay between the induced electric field by electron-electron interactions and the interlayer delocalization of the wave-functions contributing most to the HHG signal. The gliding of a bilayer is also found to affect the high-harmonic emission. Our results will have important ramifications for the experimental study of monolayer and few-layer two-dimensional materials beyond the case of hexagonal BN studied here as the result we found arew generic and applicable to all 2D semiconducting multilayer systems.
The thermal conductivity of suspended few-layer hexagonal boron nitride (h-BN) was measured using a micro-bridge device with built-in resistance thermometers. Based on the measured thermal resistance values of 11-12 atomic layer h-BN samples with sus
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