Intervalley biexcitons and many-body effects in monolayer MoS2

Abstract

Interactions between two excitons can result in the formation of bound quasiparticles, known as biexcitons. Their properties are determined by the constituent excitons, with orbital and spin states resembling those of atoms. Monolayer transition metal dichalcogenides (TMDs) present a unique system where excitons acquire a new degree of freedom, the valley pseudospin, from which a novel intervalley biexciton can be created. These biexcitons comprise two excitons from different valleys, which are distinct from biexcitons in conventional semiconductors and have no direct analogue in atomic and molecular systems. However, their valley properties are not accessible to traditional transport and optical measurements. Here, we report the observation of intervalley biexcitons in the monolayer TMD MoS2 using ultrafast pump-probe spectroscopy. By applying broadband probe pulses with different helicities, we identify two species of intervalley biexcitons with large binding energies of 60 meV and 40 meV. In addition, we also reveal effects beyond biexcitonic pairwise interactions in which the exciton energy redshifts at increasing exciton densities, indicating the presence of many-body interactions among them.

Accepted in Physical Review B

References in corpus (21)

• Valley polarization in MoS2 monolayers by optical pumping
• Synthesis of Large-Area MoS2 Atomic Layers with Chemical Vapor Deposition
• Exciton Binding Energy and Nonhydrogenic Rydberg Series in Monolayer WS2
• The Valley Hall Effect in MoS2 Transistors
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Tightly bound excitons in monolayer WSe2
• Optical properties of graphene
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• The optical conductivity of graphene in the visible region of the spectrum
• Exciton Binding Energy of Monolayer WS2
• Non-linear Optical Spectroscopy of Excited Exciton States for Efficient Valley Coherence Generation in WSe2 Monolayers
• Valley-selective optical Stark effect in monolayer WS2
• Large spin splitting in the conduction band of transition metal dichalcogenide monolayers
• Probing excitonic states in ultraclean suspended two-dimensional semiconductors by photocurrent spectroscopy
• Exciton-exciton annihilation in MoSe2 monolayers
• Valley depolarization due to inter- and intra-valley electron-hole exchange interactions in monolayer MoS${}_2$
• Ultrafast Generation of Pseudo-magnetic Field for Valley Excitons in WSe2 Monolayers
• Exciton Valley Dynamics probed by Kerr Rotation in WSe2 Monolayers
• Trion induced negative photoconductivity in monolayer MoS2
• Coherent Electronic Coupling in Atomically Thin MoSe2
• Exciton complexes in low dimensional transition metal dichalcogenides

Cited by in corpus (52)

• Excitons in atomically thin transition metal dichalcogenides
• Photo-Induced Bandgap Renormalization Governs the Ultrafast Response of Single-Layer MoS2
• Binding energies of exciton complexes in transition metal dichalcogenides and effect of dielectric environment
• Charge-tuneable biexciton complexes in monolayer WSe${}_2$
• Hundredfold Enhancement of Light Emission via Defect Control in Monolayer Transition-Metal Dichalcogenides
• Neutral and Charged Inter-Valley Biexcitons in Monolayer MoSe${}_2$
• Exciton Dynamics in Monolayer Transition Metal Dichalcogenides
• Fundamental Limits of Exciton-Exciton Annihilation for Light Emission in Transition Metal Dichalcogenide Monolayers
• Observation of exciton redshift-blueshift crossover in monolayer WS2
• Biexciton fine structure in monolayer transition metal dichalcogenides
• Large, valley-exclusive Bloch-Siegert shift in monolayer WS2
• Exciton-exciton interaction in transition-metal dichalcogenide monolayers
• Diffusion quantum Monte Carlo study of excitonic complexes in two-dimensional transition-metal dichalcogenides
• Binding energies of trions and biexcitons in two-dimensional semiconductors from diffusion quantum Monte Carlo calculations
• Broadband Femtosecond Transient Absorption Spectroscopy for CVD MoS2 monolayer
• Zeeman Splitting and Inverted Polarization of Biexciton Emission in Monolayer WS2
• Optically discriminating carrier-induced quasiparticle band gap and exciton energy renormalization in monolayer MoS2
• Exciton-Scattering-Induced Dephasing in Two-Dimensional Semiconductors
• Dark excitons and the elusive valley polarization in transition metal dichalcogenides
• Room-Temperature Electron-Hole Liquid in Monolayer MoS2
• Room temperature observation of biexcitons in exfoliated WS2 monolayers
• Ultra-low power threshold for laser induced changes in optical properties of 2D Molybdenum dichalcogenides
• Observation of intervalley biexcitonic optical Stark effect in monolayer WS2
• Oxygen passivation mediated tunability of trion and excitons in MoS${}_2$
• Excitons, trions, and biexcitons in transition metal dichalcogenides: magnetic field dependence
• Trion and Biexciton in Monolayer Transition Metal Dichalcogenides
• Theory of intervalley Coulomb interactions in monolayer transition-metal dichalcogenides
• Nonlinear interactions of dipolar excitons and polaritons in MoS2 bilayers
• Extracting Quantitative Dielectric Properties from Pump-Probe Spectroscopy
• Review of Ultrafast Spectroscopy Studies of Valley Carrier Dynamics in Two Dimensional Semiconducting Transition Metal Dichalcogenides
• Larger than 80% Valley Polarization of Free Carriers in Singly-Oriented Single Layer WS${}_2$ on Au(111)
• Few-body systems in condensed matter physics
• Electrical control of inter-layer excitons in van der Waals heterostructures
• Broadband pump-probe study of biexcitons in chemically exfoliated layered WS${}_2$
• Interaction-driven transport of dark excitons in 2D semiconductors with phonon-mediated optical readout
• Electronic and Optical properties of transition metal dichalcogenides under symmetric and asymmetric field-effect doping
• Direct Measurement of Biexcitons in Monolayer WS2
• Room Temperature Terahertz Electroabsorption Modulation by Excitons in Monolayer Transition Metal Dichalcogenides
• Excitonic complexes in anisotropic atomically thin two-dimensional materials: black phosphorus and TiS${}_3$
• Optical absorption in disordered monolayer molybdenum disulfide
• Controlling valley splitting and Polarization of dark- and bi-excitons in monolayer WS${}_2$ by a tilted magnetic field
• Probing biexciton in monolayer WS${}_2$ through controlled many-body interaction
• Coherent Dynamics of Floquet-Bloch States in Monolayer WS2 Reveals Fast Adiabatic Switching
• Combined tensor network/cluster expansion method using logic gates: Illustrated for (bi-)excitons by a single layer MoS${}_2$ model system
• Pump-triple sum-frequency-probe spectroscopy of transition metal dichalcogenides
• Spin transport in n-type single-layer transition metal dichalcogenides
• Numerical Investigation of Triexciton Stabilization in Diamond with Multiple Valleys and Bands
• Pairing of electro-magnetic bosons under spin-orbit coupling
• Signatures of defect-localized charged excitons in the photoluminescence of monolayer molybdenum disulfide
• Electrostatic control of the trion fine structure in transition metal dichalcogenide monolayers
• Dissecting intervalley coupling mechanisms in monolayer transition metal dichalcogenides
• Controllable fusion of electromagnetic bosons in two-dimensional semiconductors