Materials World Network: Classical and Quantum Optical Metamaterials by Combining Top-down and Bottom-up Fabrication Techniques

技术概述：得益于微纳米加工技术的进步，超材料的研究已经从微波扩展到太赫兹和光学频率。缩小超材料的尺寸以满足光学频率，为一类新的超材料铺平了道路，即量子超材料，这可能对电信、光学成像、能量收集、医疗保健和国土安全等广泛应用产生深远影响。然而，光学超材料领域的进一步突破受到以下几个因素的阻碍：(1)目前自上而下的制造技术在几纳米尺度上设计结构的能力；(2)自下而上的纳米加工方法缺乏长程排序；(3)金属基光学超材料的光损耗；(4)光学超材料在低光子水平下缺乏光学控制。在这个项目中，科学家们的目标是通过结合自顶向下和自底向上的纳米制造技术来制造光学超材料，并通过将超材料扩展到量子状态来减少损耗，并引入超越经典超材料的新型光学控制方案来解决上述问题。该项目联合了三个合作者，两个在英国，一个在美国，共同研究新型经典和量子光学超材料的制造、表征和建模。这个合作小组的核心理由是，它匹配了一个在大规模纳米制造方面具有专业知识的英国小组，一个在非线性光学方面具有证明理论能力的英国小组，以及一个在各种光学表征技术方面具有证明记录的美国小组。非技术概述：超材料是模仿物质秩序的人造材料。超材料由人工设计的“原子”和“分子”组成，可以设计成具有天然材料无法获得的光学特性。超材料提供了一个新颖的平台，可以随心所欲地控制光线，具有潜在的应用前景，如超越成像衍射极限的强大成像透镜，以及使外界观察者看不见物体的隐形斗篷。通过引入一种新颖的纳米制造范式，该合作项目旨在解决阻碍超材料实际应用的问题，并弥合实验室概念验证演示与现实世界应用之间的差距。这里将要进行的研究有几个领域具有广泛的影响。首先，它将促进基础材料科学的跨学科研究，包括制造、材料物理、光学物理和理论。其次，它将使位于美国和英国的三家拥有悠久互动历史、专业知识和能力互补的集团能够开展合作。这项工作为研究生和本科生提供了在国际环境中合作和旅行的机会。第三，该项目有具体的计划和程序来寻找不同的学生合作者。第四，该项目使学生能够通过长期访问和短途旅行与一个主要的国家实验室合作，即劳伦斯伯克利实验室，其中一名pi是学术人员，以及伦敦纳米技术中心，伦敦大学学院和伦敦帝国理工学院共享的英国首屈一指的纳米制造设施。本项目由电子与光子材料项目和材料研究部特殊项目办公室支持。

TECHNICAL SUMMARY:Benefiting from advancement of micro and nanofabrication tools, the research in metamaterials has been recently extended from microwave to terahertz and optical frequencies. The scale-down of metamaterials to meet optical frequencies, paves the way for a new class of metamaterials, namely quantum metamaterials, which could have a profound impact on a broad range of applications in telecommunication, optical imaging, energy harvesting, health care, and homeland security. However, further breakthrough in the field of optical metamaterials is hindered by several factors: (1) the capability of current top-down fabrication techniques to engineer structures at a few nanometers scale; (2) lack of long range ordering by using the bottom up nanofabrication approaches; (3) optical loss in the metal-based optical metamaterials; (4) lack of optical control at low photon levels in optical metamaterials. In this project, scientists aim to solve the above issues by combining top-down and bottom-up nanofabrication techniques for the manufacturing of optical metamaterials, and by extending metamaterials to the quantum regime to reduce the loss and to introduce novel optical control schemes that go beyond classical metamaterials. This project combines synergistically three collaborators, two in the UK and one in the US, to investigate the fabrication, characterization and modeling of novel classical and quantum optical metamaterials. The central rationale for this collaborative group is that it matches a UK group with expertise in large scale nanofabrication, a UK group in demonstrated theoretical capabilities in nonlinear optics, with a US group with demonstrated record of various optical characterization techniques. NON-TECHNICAL SUMMARY:Metamaterials are man-made materials that mimic the order of the matters. Metamaterials consist of artificially engineered "atoms" and "molecules", which can be designed to show optical properties unattainable from naturally occurring materials. Metamaterials present a novel platform for controlling light at one's will with potential applications such as a powerful imaging lens that beats the imaging diffraction limit and an invisibility cloak that renders object invisible to outside observers. By introducing a novel nanofabrication paradigm, this collaborative project aims at solving the issues that hinder the practical application of metamaterials, and bridging the gap between the proof-of-concept demonstrations in the laboratory to real world applications. The research to be undertaken here has several areas of broad impact. First, it will foster an interdisciplinary examination of the fundamental materials science, which includes fabrication, materials physics, optical physics, and theory. Second it will enable three groups in the US and the UK, with a strong history of interactions and complementary expertise and capabilities to collaborate. This work involves the opportunity for both graduate and undergraduate students to collaborate and travel in an international setting. Third, the program has concrete plans and procedures to seek out recruitment of diverse student collaborators. Fourth, the project enables students to collaborate via extended visits and shorter trips with a major National Laboratory, i.e. Lawrence Berkeley Lab, where one of the PIs was an academic staff, as well as the London Centre for Nanotechnology, UK's premier nanofabrication facility shared by the University College London and Imperial College London.This project is supported by the Electronic and Photonic Materials program and Office of Special Programs, Division of Materials Research.