{"title":"Revealing Ultrafast Optical Nonlinearity of Trapped Exciton Polaritons in Atomically Thin Semiconductors","authors":"Yuan Luo, Yutian Peng, Lingyu Tian, Zhiyuan An, Haiyun Liu, Yuzhong Chen, Sanjib Ghosh, Qihua Xiong","doi":"10.1021/acs.nanolett.4c04195","DOIUrl":null,"url":null,"abstract":"Nonlinearities are fundamental to modern optical technologies. Exciton polaritons in semiconductor microcavities provide a promising route to strong nonlinearities. Monolayer TMDs, with tightly bound excitons and strong oscillator strength, enable polaritonic phenomena under ambient conditions but face challenges from weak polariton interactions due to small exciton Bohr radius. Although spatial confinement can boost polariton nonlinearity, the dynamics of trapped polaritons remain underexplored. Here we study the transient nonlinearities of confined polaritons in monolayer WS<sub>2</sub> mesa cavities. We observe increasingly pronounced blueshifts within the first few picoseconds as trapping sizes decrease or excitonic fractions increase. Furthermore, our findings reveal that exciton–photon detuning, not trapping size, predominantly influences the time to reach the peak of transient nonlinearity. This insight aligns with the experimentally observed and theoretically simulated relaxation dynamics of trapped polaritons. Our findings pave the way for developing ultrafast all-optical polaritonic devices in TMD systems.","PeriodicalId":53,"journal":{"name":"Nano Letters","volume":"78 1","pages":""},"PeriodicalIF":9.6000,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nano Letters","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1021/acs.nanolett.4c04195","RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Nonlinearities are fundamental to modern optical technologies. Exciton polaritons in semiconductor microcavities provide a promising route to strong nonlinearities. Monolayer TMDs, with tightly bound excitons and strong oscillator strength, enable polaritonic phenomena under ambient conditions but face challenges from weak polariton interactions due to small exciton Bohr radius. Although spatial confinement can boost polariton nonlinearity, the dynamics of trapped polaritons remain underexplored. Here we study the transient nonlinearities of confined polaritons in monolayer WS2 mesa cavities. We observe increasingly pronounced blueshifts within the first few picoseconds as trapping sizes decrease or excitonic fractions increase. Furthermore, our findings reveal that exciton–photon detuning, not trapping size, predominantly influences the time to reach the peak of transient nonlinearity. This insight aligns with the experimentally observed and theoretically simulated relaxation dynamics of trapped polaritons. Our findings pave the way for developing ultrafast all-optical polaritonic devices in TMD systems.
期刊介绍:
Nano Letters serves as a dynamic platform for promptly disseminating original results in fundamental, applied, and emerging research across all facets of nanoscience and nanotechnology. A pivotal criterion for inclusion within Nano Letters is the convergence of at least two different areas or disciplines, ensuring a rich interdisciplinary scope. The journal is dedicated to fostering exploration in diverse areas, including:
- Experimental and theoretical findings on physical, chemical, and biological phenomena at the nanoscale
- Synthesis, characterization, and processing of organic, inorganic, polymer, and hybrid nanomaterials through physical, chemical, and biological methodologies
- Modeling and simulation of synthetic, assembly, and interaction processes
- Realization of integrated nanostructures and nano-engineered devices exhibiting advanced performance
- Applications of nanoscale materials in living and environmental systems
Nano Letters is committed to advancing and showcasing groundbreaking research that intersects various domains, fostering innovation and collaboration in the ever-evolving field of nanoscience and nanotechnology.