Ultrafast Generation of Pseudo-magnetic Field for Valley Excitons in WSe2 Monolayers

Abstract

A new degree of freedom, the valley pseudospin, emerges in atomically thin two-dimensional transition metal dichalcogenides (MX2) and has attracted great scientific interest. The capability to manipulate the valley pseudospin, in analogy to the control of spin in spintronics, can open up exciting opportunities in valleytronics. Here we demonstrate that an ultrafast and ultrahigh valley pseudomagnetic field can be generated using circularly polarized femtosecond pulses to selectively control the valley degree of freedom in monolayer MX2. Employing ultrafast pump-probe spectroscopy, we observed a pure and valley-selective optical Stark effect in WSe2 monolayers from the non-resonant pump, which instantaneously lift the degeneracy of valley exciton transitions without any dissipation. The strength of the optical Stark effect scales linearly with both the pump intensity and the inverse of pump detuning. An energy splitting more than 10 meV between the K and K_prime valley transitions can be achieved, which corresponds to an effective pseudomagnetic field over 170 Tesla. Our study demonstrates efficient and ultrafast control of the valley excitons with optical light, and opens up the possibility to coherent manipulate the valley polarization for quantum information applications.

References in corpus (17)

• Atomically thin MoS2: A new direct-gap semiconductor
• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Control of valley polarization in monolayer MoS2 by optical helicity
• Valley polarization in MoS2 monolayers by optical pumping
• MoS_2 as an ideal material for valleytronics: valley-selective circular dichroism and valley Hall effect
• The Valley Hall Effect in MoS2 Transistors
• Measurement of the Optical Conductivity of Graphene
• Optical Generation of Excitonic Valley Coherence in Monolayer WSe2
• Driven coherent oscillations of a single electron spin in a quantum dot
• Large-Area Aiming Synthesis of WSe2 Monolayers
• Magnetic Control of Valley Pseudospin in Monolayer WSe2
• Quasiparticle band structures and optical properties of strained monolayer MoS2 and WS2
• Valley Zeeman Effect in Elementary Optical Excitations of a Monolayer WSe2
• Breaking of valley degeneracy by magnetic field in monolayer MoSe2
• AC-Stark Shift and Dephasing of a Superconducting Qubit Strongly Coupled to a Cavity Field
• Valley Carrier Dynamics in Monolayer Molybdenum Disulphide from Helicity Resolved Ultrafast Pump-probe Spectroscopy
• Effective lattice Hamiltonian for monolayer MoS2 : Tailoring electronic structure with perpendicular electric and magnetic fields

Cited by in corpus (101)

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• Valley Splitting and Polarization by the Zeeman Effect in Monolayer MoSe2
• Nonthermal pathways to ultrafast control in quantum materials
• Enhanced valley splitting in monolayer WSe2 due to magnetic exchange field
• Valley Manipulation by Optically Tuning the Magnetic Proximity Effect in WSe${}_2$/CrI${}_3$ Heterostructures
• Topological Exciton Bands in Moiré Heterojunctions
• Engineering symmetry breaking in two-dimensional layered materials
• Valley excitons in two-dimensional semiconductors
• Exciton band structure of monolayer MoS2
• Theory of optical absorption by interlayer excitons in transition metal dichalcogenide heterobilayers
• Light-induced emergent phenomena in 2D materials and topological materials
• Ultrafast Manipulation of Valley Pseudospin
• Pseudospin-selective Floquet band engineering in black phosphorus
• Enhanced Light-Matter Interaction in Two-Dimensional Transition Metal Dichalcogenides
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• Thickness dependence of work function, ionization energy, and electron affinity of Mo and W dichalcogenides from DFT and GW calculations
• Intervalley biexcitons and many-body effects in monolayer MoS2
• Valley Magnetoelectricity in Single-Layer MoS2
• Control of Exciton Valley Coherence in Transition Metal Dichalcogenide Monolayers
• Dissociation of two-dimensional excitons in monolayer WSe2
• Polarization and valley switching in monolayer group-IV monochalcogenides
• Giant Zeeman splitting inducing near-unity valley polarization in van der Waals heterostructures
• Large, valley-exclusive Bloch-Siegert shift in monolayer WS2
• The ultrafast onset of exciton formation in 2D semiconductors
• Dynamical Time-Reversal Symmetry Breaking and Photo-Induced Chiral Spin Liquids in Frustrated Mott Insulators
• Light matter interaction in transition metal dichalcogenides and their heterostructures
• Experimental observation of hidden Berry curvature in inversion-symmetric bulk 2H-WSe2
• Routing of valley photons in a WS2 monolayer via delocalized Bloch modes of in-plane inversion-symmetry broken photonic crystal slabs
• All-Optical Materials Design of Chiral Edge Modes in Transition-Metal Dichalcogenides
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• Manipulating Spin-polarized Photocurrent in 2D Transition Metal Dichalcogenides
• Spin-orbit coupling induced valley Hall effects in transition-metal dichalcogenides
• Room-temperature coherent optical manipulation of single-hole spins in solution-grown perovskite quantum dots
• Tunable point nodes from line node semimetals via application of light
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• Opto-valleytronic imaging of atomically thin semiconductors
• Floquet Weyl semimetals in light-irradiated type-II and hybrid line-node semimetals
• Terahertz phonon engineering with van der Waals heterostructures
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• Valley-dependent Exciton Fine Structure and Autler-Townes Doublets from Berry Phases in Monolayer Molybdenum Diselenide
• Floquet dynamics in two-dimensional semi-Dirac semimetals and three-dimensional Dirac semimetals
• Inter-valley dark trion states with spin lifetimes of 150 ns in WSe${}_2$
• Optically-Controlled Orbitronics on a Triangular Lattice
• Photoinduced topological phase transition from a crossing-line nodal semimetal to a multiple-Weyl semimetal
• Optical control of valley Zeeman effect through many-exciton interactions
• Valley-selective optical Stark effect probed by Kerr rotation
• Floquet topological insulator phase in a Weyl semimetal thin film with disorder
• Review of Ultrafast Spectroscopy Studies of Valley Carrier Dynamics in Two Dimensional Semiconducting Transition Metal Dichalcogenides
• Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2 Nanoparticles
• Edge pseudo-magnetoplasmons
• Percolative switching in transition metal dichalcogenide field-effect transistors at room temperature
• Valley Degree of Freedom in Two-Dimensional van der Waals Materials
• Valley Polarization-Electric Dipole Interference and Nonlinear Chiral Selection Rules in Monolayer WSe${}_2$
• Ultrafast valley-selective coherent optical manipulation with excitons in WSe${}_2$ and MoS${}_2$ monolayers
• Quantum-electrodynamical approach to the exciton spectrum in Transition-Metal Dichalcogenides
• Vibrational dichroism of chiral valley phonons
• Disorder Dependent Valley Properties in Monolayer WSe2
• Exciton-coherence generation through diabatic and adiabatic dynamics of Floquet state
• Room Temperature Terahertz Electroabsorption Modulation by Excitons in Monolayer Transition Metal Dichalcogenides
• Optical spin pumping induced pseudo-magnetic field in two dimensional heterostructures
• Polaritonic Chern insulators in monolayer semiconductors
• Excitonic Bloch-Siegert shift in CsPbI3 perovskite quantum dots
• Pseudospin Electronics in Phosphorene Nanoribbons
• Coherent Dynamics of Floquet-Bloch States in Monolayer WS2 Reveals Fast Adiabatic Switching
• Incoherent phonon population and exciton-exciton annihilation in monolayer WS2 revealed by time-resolved spontaneous Raman scattering
• Probing valley filtering effect by Andreev reflection in zigzag graphene nanoribbon
• Manipulating the symmetry of photon-dressed electronic states
• Interaction induced AC-Stark shift of exciton-polaron resonances
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• Quantum interference between the optical Stark effect and resonant harmonic generation in WS2
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• Expeditious computation of nonlinear optical properties of arbitrary order with native electronic interactions in the time domain
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• Photonics in Flatland: Challenges and Opportunities for Nanophotonics with 2D Semiconductors
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• Direct measurement of broken time-reversal symmetry in centrosymmetric and non-centrosymmetric atomically thin crystals with nonlinear Kerr rotation
• Ultrafast Coherent Bandgap Modulation Probed by Parametric Nonlinear Optics
• Chiral excitonic systems in twisted bilayers from Förster coupling and unconventional excitonic Hall effects
• Ultrafast room-temperature valley manipulation in silicon and diamond
• Multistable excitonic Stark effect
• Direct observation of internal quantum transitions and femtosecond radiative decay of excitons in monolayer WSe_2
• Single Quantum Emitters in Monolayer Semiconductors
• Excitonic Transport and Intervalley Scattering in Exfoliated MoSe2 Monolayer Revealed by Four-Wave-Mixing Transient Grating Spectroscopy
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