Probing Landau levels of strongly interacting massive Dirac electrons in layer-polarized MoS${}_2$

Abstract

Monolayer transition metal dichalcogenides are recently emerged 2D electronic systems with various novel properties, such as spin-valley locking, circular dichroism, valley Hall effects, Ising superconductivity. The reduced dimensionality and large effective masses further produce unconventional many-body interaction effects. Although recent hole transport measurements in WSe${}_2$ indicate strong interactions in the valence bands, many-body interaction effects, particularly in the conduction bands, remain elusive to date. Here, for the first time, we perform transport measurements up to a magnetic field of $29$T to study the massive Dirac electron Landau levels (LL) in layer-polarized MoS${}_2$ samples with mobilities of $22000$cm${}^2$/(V$\cdot$s) at $1.5$K and densities of $\sim 10^{12}$cm${}^{-2}$. With decreasing the density, we observe LL crossing induced valley ferrimagnet-to-ferromagnet transitions, as a result of the interaction enhancement of the g-factor from $5.64$ to $21.82$. Near integer ratios of Zeeman-to-cyclotron energies, we discover LL anticrossings due to the formation of quantum Hall Ising ferromagnets, the valley polarizations of which appear to be reversible by tuning the density or an in-plane magnetic field. Our results provide compelling evidence for many-body interaction effects in the conduction bands of monolayer MoS${}_2$ and establish a fertile ground for exploring strongly correlated phenomena of massive Dirac electrons.

arXiv comment21 pages, 4 figures

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Cited by in corpus (21)

• Lattice reconstruction induced multiple ultra-flat bands in twisted bilayer WSe2
• Shubnikov-de Haas oscillations in optical conductivity of monolayer MoSe${}_2$
• Effects of Hexagonal Boron Nitride Encapsulation on the Electronic Structure of Few-layer MoS${}_2$
• Gate-Controlled Quantum Dots Based on Two-Dimensional Materials
• Absence of inter-layer tunnel coupling of $K$-valley electrons in bilayer MoS${}_2$
• Landau-quantized excitonic absorption and luminescence in a monolayer valley semiconductor
• Controlling exciton many-body states by the electric-field effect in monolayer MoS${}_2$
• Spontaneous valley polarization of interacting carriers in a monolayer semiconductor
• Tunable spin-valley coupling in layered polar Dirac metals
• Intervalley Polaron in Atomically Thin Transition Metal Dichalcogenides
• Valley-Filling Instability and Critical Magnetic Field for Interaction-Enhanced Zeeman Response in Doped WSe${}_2$ Monolayers
• Weak localization in boron nitride encapsulated bilayer MoS${}_2$
• Exciton solid in bilayer two dimensional electron-hole systems
• Evidence of the Coulomb gap in the density of states of MoS${}_2$
• Influence of atomic relaxations on the moiré flat band wavefunctions in antiparallel twisted bilayer WS${}_{\text{2}}$
• High-field Studies on Layered Magnetic and Polar Dirac Metals
• Quantum solid phase and Coulomb drag in two-dimensional electron-electron bilayers of MoS2
• Metal-insulator transitions in bilayer electron-hole systems in transition metal dicalcogenides
• Density-dependent spin susceptibility and effective mass in monolayer MoSe2
• High magnetic field spin-valley-split Shubnikov-de Haas oscillations in a WSe${}_2$ monolayer
• Spontaneous Breaking of the SU(3) Flavor Symmetry in a Quantum Hall Valley Nematic