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Ultrastrong Coupling of Band-Nested Excitons in Few-Layer Molybdenum Disulphide

Mesoscale and Nanoscale Physics 2022-05-02 v1 Materials Science Optics

Abstract

The two-dimensional transition-metal dichalcogenides (2D TMDCs) are an intriguing platform for studying light-matter interactions because they combine the electronic properties of conventional semiconductors with the optical resonances found in organic systems. However, the coupling strengths demonstrated in strong exciton-polariton coupling remain much lower than those found in organic systems. In this paper, we take on a new approach by utilizing the large oscillator strength of the above-band gap C exciton in few-layer molybdenum disulphide (FL-MoS2\text{FL-MoS}_2). We show a k-space Rabi splitting of 293 meV when coupling FL-MoS2\text{FL-MoS}_2 C excitons to surface plasmon polaritons at room temperature. This value is 11% of the uncoupled exciton energy (2.67 eV or 464 nm), ~2x what is typically seen in the TMDCs, placing the system in the ultrastrong coupling regime. Our results take a step towards finally achieving the efficient quantum coherent processes of ultrastrong coupling in a CMOS-compatible system -- the 2D TMDCs -- in the visible spectrum.

Keywords

Cite

@article{arxiv.2204.13768,
  title  = {Ultrastrong Coupling of Band-Nested Excitons in Few-Layer Molybdenum Disulphide},
  author = {Aaron H. Rose and Taylor J. Aubry and Hanyu Zhang and Jao van de Lagemaat},
  journal= {arXiv preprint arXiv:2204.13768},
  year   = {2022}
}