Valley Polarization in Size-Tunable Monolayer Semiconductor Quantum Dots

Abstract

Three-dimensional confinement allows semiconductor quantum dots (QDs) to exhibit size-tunable electronic and optical properties that enable a wide range of opto-electronic applications from displays, solar cells and bio-medical imaging to single-electron devices. Additional modalities such as spin and valley properties can provide further degrees of freedom requisite for quantum information and spintronics. When seeking to combine these material features into QD structures, however, confinement can cause hybridization that inhibits the robustness of these emergent properties for insertion into quantum devices. Here, we show that a new class of laterally-confined materials, monolayer MoS${}_2$ QDs, can be created through top-down nanopatterning of an atomically-thin two-dimensional semiconductor so that they exhibit the same valley polarization as in a continuous monolayer sheet. Semiconductor-compatible nanofabrication process allows for these low-dimensional materials to be integrated into complex systems, an important feature for advancing quantum information applications. The inherited bulk spin and valley properties, the size dependence of excitonic energies, and the ability to fabricate MoS${}_2$ QDs using semiconductor-compatible processing suggest that monolayer semiconductor QDs have the potential to be multimodal building blocks of integrated quantum information and spintronics systems.

13 pages, 4 figures

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Cited by in corpus (13)

• All van der Waals Integrated Nanophotonics
• Roadmap for Photonics with 2D Materials
• Deterministic positioning of colloidal quantum dots on silicon nitride nanobeam cavities
• Cavity nonlinear optics with layered materials
• Strong photon antibunching in weakly nonlinear two-dimensional exciton-polaritons
• Inlaid ReS2 Quantum Dots in Monolayer MoS2
• Charged exciton kinetics in monolayer MoSe${}_2$ near ferroelectric domain walls in periodically poled LiNbO${}_3$
• Quantum many-body simulation using monolayer exciton-polaritons in coupled-cavities
• Single exciton trapping in an electrostatically defined 2D semiconductor quantum dot
• Anomalous energy shift of laterally confined two-dimensional excitons
• Width-dependent Photoluminescence and Anisotropic Raman Spectroscopy from Monolayer MoS${}_2$ Nanoribbons
• Low-Temperature Annihilation Rate for Quasi-Localized Excitons in Monolayer MoS2
• Hyperfine interaction in atomically thin transition metal dichalcogenides