Interaction-driven transport of dark excitons in 2D semiconductors with phonon-mediated optical readout

Abstract

The growing field of quantum information technology requires propagation of information over long distances with efficient readout mechanisms. Excitonic quantum fluids have emerged as a powerful platform for this task due to their straightforward electro-optical conversion. In two-dimensional transition metal dichalcogenides, the coupling between spin and valley provides exciting opportunities for harnessing, manipulating and storing bits of information. However, the large inhomogeneity of single layers cannot be overcome by the properties of bright excitons, hindering spin-valley transport. Nonetheless, the rich band structure supports dark excitonic states with strong binding energy and longer lifetime, ideally suited for long-range transport. Here we show that dark excitons can diffuse over several micrometers and prove that this repulsion-driven propagation is robust across non-uniform samples. The long-range propagation of dark states with an optical readout mediated by chiral phonons provides a new concept of excitonic devices for applications in both classical and quantum information technology.

References in corpus (9)

• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• Dark excitons in transition metal dichalcogenides
• Exciton-exciton interaction in transition-metal dichalcogenide monolayers
• Momentum-Dark Intervalley Exciton in Monolayer Tungsten Diselenide Brightened via Chiral Phonon
• Nonclassical Exciton Diffusion in Monolayer WSe2
• Excitonic complexes in $n$-doped WS${}_2$ monolayer
• Visualization of dark excitons in semiconductor monolayers for high-sensitivity strain sensing
• Intervalley electron-hole exchange interaction and impurity-assisted recombination of indirect excitons in WS${}_2$ and WSe${}_2$ monolayers

Cited by in corpus (5)

• Influence of Dynamical Floquet Spectrum on the Plasmon Excitations and Exchange Energy of tilted monolayer 1T${}^{\prime }$MoS${}_2$
• Observation of quasi-steady dark excitons and gap phase in a doped semiconductor
• Correlated phases of moat-band excitons in two dimensions
• Sub-diffraction-resolved spatial distribution of emitting excitons in STM-induced luminescence of 2D semiconductors via Richardson-Lucy deconvolution
• Emergence of new optical resonances in single-layer transition metal dichalcogenides with atomic-size phase patterns