Topological quantum optics

物质的拓扑相深刻地影响了我们对凝聚态物质的理解。他们的影响范围从理解整数量子霍尔效应中电导率平台的普遍性到设想容错量子计算机的新硬件平台。在人工系统中模拟物质的这些相——例如冷原子、光子纳米结构、光力学和机械阵列——在过去的几年里已经成为一种探索拓扑物理的强大方法，超越了物理上在固态中可以达到的范围。在这些合成平台中，光子系统由于其多功能性和技术相关性而显示出巨大的潜力。这导致了一个名为拓扑光子学的研究领域的蓬勃发展，该领域的重点是对制造缺陷更具弹性的新一代光子器件的概念-包括拓扑保护激光器-以及对凝聚态物质中没有对应部分的奇异拓扑相的仿真，例如涉及合成尺寸，无序或驱动和耗散的相。目前，这个快速发展的研究领域最有希望的前景之一是将其探索扩展到量子状态。事实上，考虑到阻碍量子器件扩展的主要障碍与相干态的极端脆弱性有关，拓扑保护——在光子和电子器件中——似乎是一项非常有价值的资产，需要迅速研究。这正是本研究计划的主要目标，该研究计划将探索在拓扑保护环境中光和物质的多体量子态的出现。为了实现这一目标，我们将采用一种双重方法，包括嵌入在硅基拓扑光子晶体中的量子发射体的a -密集系综，以及半导体单层中的B-相关电子态，两者都与拓扑光子模式强耦合。为了应对这一雄心勃勃的挑战，我们将遵循由三个主要研究轴组成的路线图。1-光子轴，将致力于硅拓扑光子晶体的制造、表征和优化设计。2-极化轴，旨在达到我们的集体激发之间的强光-物质耦合机制，包括发射体和相关电子态的密集集合，以及我们的拓扑保护光子模式。3-封锁机制，我们将推动我们的光子结构的质量因子，以达到一个单一的激发量子填充我们的拓扑保护极化模式的机制。这一原创研究项目预计将对量子技术产生重大影响，使我们能够更好地了解拓扑系统可以在多大程度上用于保护量子器件免受噪声和其他失相源的影响。

Topological phases of matter have profoundly impacted our understanding of condensed matter. Their influence ranges from understanding the universality of the conductivity plateaus in the integer quantum Hall effect to envisioning new hardware platforms for fault-tolerant quantum computers. The emulation of these phases of matter in artificial systems - e.g. cold atoms, photonic nanostructures, and optomechanical and mechanical arrays - has emerged in the last few years as a powerful approach for exploring topological physics beyond what is physically reachable in the solid-state. Among these synthetic platforms, photonic systems have shown a huge potential, thanks to their versatility and technological relevance. This has led to the blooming of a research field called topological photonics which focuses on the conception of new generations of photonic devices more resilient to fabrication defects - including topologically protected lasers - and on the emulation of exotic topological phases that have no counter-parts in condensed matter, e.g. phases involving synthetic dimensions, disorder or drive and dissipation. Right now, one of the most promising perspectives of this rapidly evolving field of research is to extend its exploration toward the quantum regime. Indeed, considering that the main hurdle hindering the scaling of quantum devices is related to the extreme fragility of coherent states, topological protection - in photonic as well as in electronic devices - appears as an extremely valuable asset that needs to be rapidly investigated. This is precisely the main objective of this research program that will explore the emergence of many-body quantum states of light and matter in topologically protected environments. To achieve this, we will follow a dual approach consisting of A- dense ensembles of quantum emitters embedded inside Si-based topological photonic crystals, and B- correlated electronic states in semiconductor monolayers, both strongly coupled to topological photonic modes. In order to tackle this very ambitious challenge, we will follow a roadmap consisting of three main axes of research. 1- The photonic axis that will aim at fabricating, characterizing, and optimizing the design of topological photonic crystals in silicon. 2- The polaritonic axis that will aim at reaching a strong light-matter coupling regime between our collective excitations, both with the dense ensembles of emitters and the correlated electronic states, and our topologically protected photonic modes. 3- The blockade regime where we will push the quality factor of our photonic structures in order to reach a regime where a single quantum of excitation populates our topologically protected polaritonic modes. This original research program is expected to have a major impact on quantum technologies, allowing us to better understand at which extent topological systems can be harnessed for protecting quantum devices from noise and other sources of dephasing.