Trion Species-Resolved Quantum Beats in MoSe2
arXiv:1709.03233 · doi:10.1021/acsnano.7b06444
Abstract
Monolayer photonic materials offer a tremendous potential for on-chip optoelectronic devices. Their realization requires knowledge of optical coherence properties of excitons and trions that have so far been limited to nonlinear optical experiments carried out with strongly inhomogenously broadened material. Here we employ h-BN encapsulated and electrically gated MoSe2 to reveal coherence properties of trion-species directly in the linear optical response. Autocorrelation measurements reveal long dephasing times up to T2=1.16+-0.05 ps for positively charged excitons. Gate dependent measurements provide evidence that the positively-charged trion forms via spatially localized hole states making this trion less prone to dephasing in the presence of elevated hole carrier concentrations. Quantum beat signatures demonstrate coherent coupling between excitons and trions that have a dephasing time up to 0.6 ps, a two-fold increase over those in previous reports. A key merit of the prolonged exciton/trion coherences is that they were achieved in a linear optical experiment, and thus are directly relevant to applications in nanolasers, coherent control, and on-chip quantum information processing requiring long photon coherence.
21 pages, 6 figures, 2 SOI figures
References in corpus (6)
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Cited by in corpus (7)
- Stark shift of excitons and trions in two-dimensional materials
- Ground and Excited Exciton Polarons in Monolayer MoSe2
- Enhanced trion emission in monolayer MoSe2 by constructing a type-I van der Waals heterostructure
- Many-body theory of optical absorption in doped two-dimensional semiconductors
- Fundamental exciton linewidth broadening in monolayer transition metal dichalcogenides
- Inter-layer charge transport controlled by exciton-trion coherent coupling
- Exciton diffusion in a hBN-encapsulated monolayer MoSe2