Imaging dynamic exciton interactions and coupling in transition metal dichalcogenides

Transition metal dichalcogenides (TMDs) are regarded as a possible material platform for quantum information science and related device applications. In TMD monolayers, the dephasing time and inhomogeneity are crucial parameters for any quantum information application. In TMD heterostructures, coupling strength and interlayer exciton lifetimes are also parameters of interest. However, many demonstrations in TMDs can only be realized at specific spots on the sample, presenting a challenge to the scalability of these applications. Here, using multi-dimensional coherent imaging spectroscopy, we shed light on the underlying physics-including dephasing, inhomogeneity, and strain-for a MoSe2 monolayer and identify both promising and unfavorable areas for quantum information applications. We, furthermore, apply the same technique to a MoSe2/WSe2 heterostructure. Despite the notable presence of strain and dielectric environment changes, coherent and incoherent coupling and interlayer exciton lifetimes are mostly robust across the sample. This uniformity is despite a significantly inhomogeneous interlayer exciton photoluminescence distribution that suggests a bad sample for device applications. This robustness strengthens the case for TMDs as a next-generation material platform in quantum information science and beyond. Published under an exclusive license by AIP Publishing.

Automated summary

TMDs are considered as a potential material platform for quantum information science, and multi-dimensional coherent imaging spectroscopy sheds light on the underlying physics for both MoSe2 monolayers and MoSe2/WSe2 heterostructures. The study identifies promising and unfavorable areas for quantum information applications, highlighting the importance of robustness in coherent and incoherent coupling for device applications. The presence of strain and dielectric environment changes does not significantly affect the interlayer exciton lifetimes, supporting TMDs as a next-generation material platform in quantum information science and beyond.