Strain engineering of exciton-polaritons in 2D Semiconductors

原子薄的二维（2D）半导体，由于它们与光的前所未有的强相互作用，已经成为光子学应用中非常有吸引力的材料平台。从基本的角度来看，他们展示了一系列广泛的现象，包括强光-物质相互作用的机制，其中系统表现出光和材料激发的特性。这种混合系统在固态量子技术中具有潜在的应用，使它们能够呈现物质和光的最佳特性。由于这些2D材料的原子厚度，应变提供了一种独特的方法来增强光电性能。这项研究的重点是使用应变来控制这些混合系统的光电特性，并探讨应变引入晶格几何时出现的特性。这种半光半物质系统的晶格可以模拟其他难以在经典计算机上模拟的量子系统。其他潜在的应用领域包括实现基于光的电路和开关，这些电路和开关可以想象地在单个光粒子的水平上操作。该项目符合NSF的“量子飞跃”的大想法。它将培训研究生和本科生，并使当地中学的学生接触光和纳米材料的奇迹。其中一个亮点是为城市学院的本科生举办的2D材料实践工作坊，以及为当地中学举办的一系列演示。技术说明激子-极化激元，电子材料激发和光子的混合态，展示了各种丰富的物理现象。 它们是固态量子非线性光子学的一个潜在的良好平台。在这个项目中，研究小组将利用2D材料承受大应变的能力来操纵嵌入原子薄半导体的光学微腔中形成的激子和激子-极化激元。通过衬底工程引入极大的应变来控制应变模式，操纵激子和极化激元扩散，最终增强它们的非线性相互作用，以实现极化激元及其晶格的关联态。具体而言，在研究中使用嵌入应变工程微腔中的2D过渡金属二硫属化物。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical DescriptionAtomically thin two-dimensional (2D) semiconductors, owing to their unprecedented strong interaction with light have become a very attractive material platform for applications in photonics. From a fundamental standpoint, they demonstrate a wide array of phenomena including the regime of strong light-matter interaction where the system exhibits both the properties of light and material excitation. Such hybrid systems have potential applications in quantum technologies in the solid state that allow them to take on the best properties of matter and light. Due to the atomic thickness of these 2D materials, strain presents a unique approach to enhance the optoelectronic properties. This research is focusing on using strain to control the optoelectronic properties of these hybrid systems and to explore emergent properties that arise when strain is introduced in a lattice geometry. Such lattice of half-light half-matter systems can enable simulation of other quantum systems which are hard to simulate on a classical computer. Other potential application areas include realizing light-based circuits and switches which could conceivably operate at the level of a single particle of light. The project aligns with the NSF Big Idea of “Quantum Leap.” It will train graduate and undergraduate students and expose students from local area middle schools to the wonders of light and nanomaterials. A highlight among the outreach activities is a hands-on 2D materials workshop for undergraduate students at City College and a series of demonstrations for local area middle school.Technical DescriptionExciton-polaritons, hybrid states of electronic material excitations and photons demonstrate a wide array of rich physical phenomena. They are a potentially good platform for solid state quantum nonlinear photonics. In this project the research team will utilize the ability of 2D materials to withstand large strains to manipulate excitons and exciton-polaritons formed in optical microcavities embedded with atomically thin semiconductors. Extremely large strain via substrate engineering is induced to control strain patterns, manipulate exciton and polariton diffusion and finally enhance their nonlinear interactions for realizing correlated states of polaritons and their lattices. Specifically, 2D transition metal dichalcogenides embedded in strain engineered microcavities are used in the studies. Their linear and non-linear optical properties are investigated using combination of steady state, time resolved and Fourier space spectroscopy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.