Valley-spin polarized Landau levels in a monolayer semiconductor

Abstract

Electrons in monolayer transition metal dichalcogenides (TMDs) possess both the valley and spin degree of freedom. These internal quantum degrees of freedom have provided an ideal laboratory for exploring both new physical phenomena and electronics and photonics applications. Valley- and spin-dependent optical and electrical properties, originated from Berry curvature effects, have been recently demonstrated. Such Berry curvature effects, together with strong spin-orbit interactions, can further generate unconventional Landau levels (LLs) under a perpendicular magnetic field that support valley- and spinpolarized chiral edge states in the quantum Hall regime. The unique LL structure, however, has not been demonstrated in TMDs. Here we report the observation of fully valley- and spin-polarized LLs in high-quality WSe2 monolayers achieved using a van der Waals heterostructure device platform. Handedness-resolved optical reflection spectroscopy has been applied to probe the inter-LL transitions at individual valleys. The LL structure has been constructed. A doping-induced mass renormalization driven by the strong Coulomb interactions has also been observed. Our results open the door for studies of the unconventional LL physics and quantum Hall effect in monolayer TMDs.

13 pages, 4 figures

References in corpus (15)

• The electronic properties of graphene
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• Tightly bound excitons in monolayer WSe2
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• Quantum Hall Ferromagnetism in Graphene
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• Valley susceptibility of an interacting two-dimensional electron system
• Unconventional Quantum Hall Effect and Tunable Spin Hall Effect in MoS2 Trilayers
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• Magneto-optics in transition metal diselenide monolayers

Cited by in corpus (10)

• Emerging Photoluminescence from the Dark-Exciton Phonon Replica in Monolayer WSe2
• Luminescent emission of excited Rydberg excitons from monolayer WSe2
• Landau-quantized excitonic absorption and luminescence in a monolayer valley semiconductor
• Spontaneous valley polarization of interacting carriers in a monolayer semiconductor
• Light-matter coupling and non-equilibrium dynamics of exchange-split trions in monolayer WS2
• Excitonic magneto-optics in monolayer transition metal dichalcogenides: From nanoribbons to two-dimensional response
• High magnetic field spin-valley-split Shubnikov-de Haas oscillations in a WSe${}_2$ monolayer
• Interaction between the small gas molecules and the defective WSe2 monolayer
• Spontaneous Valley Splitting and Valley Pseudospin Field Effect Transistor of Monolayer VAgP2Se6
• How the dynamic of photo-induced gate screening complicates the investigation of valley physics in 2D materials