近日，丹麦技术大学的Søren Stobbe&Ali Nawaz Babar及其研究小组取得一项新进展。经过不懈努力，他们实现具有原子尺度约束的自组装光子腔。相关研究成果已于2023年12月6日在国际权威学术期刊《自然》上发表。

该研究团队利用表面力，包括卡西米尔-范德华相互作用，来确定自组装和自对准悬浮硅纳米结构。尽管只使用了传统光刻和蚀刻技术，但其空洞特征远低于传统光刻和蚀刻的长度尺度。该方法具有显著的鲁棒性，自组装阈值单调依赖于数千个被测器件的所有控制参数。

研究人员通过制造任何其他已知方法都无法制造的纳米结构来说明这些概念的潜力，例如波导耦合高Q硅光子腔，将电信光子约束在2nm气隙内，长宽比为100，对应于比衍射极限低100倍以上的模体积。扫描透射电子显微镜测量证实了制造亚纳米尺寸器件的能力。这项研究工作是迈向新一代制造技术的第一步，该技术将自组装的原子尺寸与平面半导体的可扩展性相结合。

据悉，尽管大分子、纳米线和二维材料等自组装纳米技术构建块的研究取得了显著进展，但合成自组装方法从纳米尺度到宏观尺度的扩展性仍然有限，与生物自组装相比存在差距。相对而言，平面半导体技术则因其固有的可扩展性产生了巨大的技术影响，但其似乎无法达到自组装的原子尺寸水平。

附：英文原文

Title: Self-assembled photonic cavities with atomic-scale confinement

Author: Babar, Ali Nawaz, Weis, Thor August Schimmell, Tsoukalas, Konstantinos, Kadkhodazadeh, Shima, Arregui, Guillermo, Vosoughi Lahijani, Babak, Stobbe, Soren

Issue&Volume: 2023-12-06

Abstract: Despite tremendous progress in research on self-assembled nanotechnological building blocks, such as macromolecules, nanowires and two-dimensional materials, synthetic self-assembly methods that bridge the nanoscopic to macroscopic dimensions remain unscalable and inferior to biological self-assembly. By contrast, planar semiconductor technology has had an immense technological impact, owing to its inherent scalability, yet it seems unable to reach the atomic dimensions enabled by self-assembly. Here, we use surface forces, including Casimir–van der Waals interactions, to deterministically self-assemble and self-align suspended silicon nanostructures with void features well below the length scales possible with conventional lithography and etching, despite using only conventional lithography and etching. The method is remarkably robust and the threshold for self-assembly depends monotonically on all the governing parameters across thousands of measured devices. We illustrate the potential of these concepts by fabricating nanostructures that are impossible to make with any other known method: waveguide-coupled high-Q silicon photonic cavities that confine telecom photons to 2nm air gaps with an aspect ratio of 100, corresponding to mode volumes more than 100 times below the diffraction limit. Scanning transmission electron microscopy measurements confirm the ability to build devices with sub-nanometre dimensions. Our work constitutes the first steps towards a new generation of fabrication technology that combines the atomic dimensions enabled by self-assembly with the scalability of planar semiconductors.

DOI: 10.1038/s41586-023-06736-8

Source: https://www.nature.com/articles/s41586-023-06736-8