Customising radiative decay dynamics of two-dimensional excitons via position- and polarisation-dependent vacuum-field interference

• Main Authors: Park, Sanghyeok, Kim, Dongha, Choi, Yun-Seok, Baucour, Arthur, Kim, Donghyeong, Yoon, Sangho, Watanabe, Kenji, Taniguchi, Takashi, Shin, Jonghwa, Kim, Jonghwan, Seo, Min-Kyo
• Format: Journal Article
• Language: English
• Published: 09-08-2022
• Subjects: Physics - Mesoscale and Nanoscale Physics; Physics - Optics
• DOI: 10.48550/arxiv.2208.04671

Embodying bosonic and electrically interactive characteristics in
two-dimensional space, excitons in transition-metal dichalcogenides (TMDCs)
have garnered considerable attention. The realisation and application of
strong-correlation effects, long-range transport, and valley-dependent
optoelectronic properties require customising exciton decay dynamics. Strains,
defects, and electrostatic doping effectively control the decay dynamics but
significantly disturb the intrinsic properties of TMDCs, such as electron band
structure and exciton binding energy. Meanwhile, vacuum-field manipulation
provides an optical alternative for engineering radiative decay dynamics.
Planar mirrors and cavities have been employed to manage the light-matter
interactions of two-dimensional excitons. However, the conventional flat
platforms cannot customise the radiative decay landscape in the horizontal TMDC
plane or independently control vacuum field interference at different pumping
and emission frequencies. Here, we present a meta-mirror resolving the issues
with more optical freedom. For neutral excitons of the monolayer MoSe2, the
meta-mirror manipulated the radiative decay rate by two orders of magnitude,
depending on its geometry. Moreover, we experimentally identified the
correlation between emission intensity and spectral linewidth. The anisotropic
meta-mirror demonstrated polarisation-dependent radiative decay control. We
expect that the meta-mirror platform will be promising to tailor the
two-dimensional distributions of lifetime, density, and diffusion of TMDC
excitons in advanced opto-excitonic applications.