Valley-selective optical Stark effect probed by Kerr rotation

Abstract

The ability to monitor and control distinct states is at the heart of emerging quantum technologies. The valley pseudospin in transition metal dichalcogenide (TMDC) monolayers is a promising degree of freedom for such control, with the optical Stark effect allowing for valley-selective manipulation of energy levels in WS${}_2$ and WSe${}_2$ using ultrafast optical pulses. Despite these advances, understanding of valley-sensitive optical Stark shifts in TMDCs has been limited by reflectance-based detection methods where the signal is small and prone to background effects. More sensitive polarization-based spectroscopy is required to better probe ultrafast Stark shifts for all-optical manipulation of valley energy levels. Here, we show time-resolved Kerr rotation to be a more sensitive probe of the valley-selective optical Stark effect in monolayer TMDCs. Compared to the established time-resolved reflectance methods, Kerr rotation is less sensitive to background effects. Kerr rotation provides a five-fold improvement in the signal-to-noise ratio of the Stark effect optical signal and a more precise estimate of the energy shift. This increased sensitivity allows for observation of an optical Stark shift in monolayer MoS${}_2$ that exhibits both valley- and energy-selectivity, demonstrating the promise of this method for investigating this effect in other layered materials and heterostructures.

9 pages, 4 figures, supplementary information

References in corpus (20)

• Coupled spin and valley physics in monolayers of MoS2 and other group-VI dichalcogenides
• Control of valley polarization in monolayer MoS2 by optical helicity
• Optical Generation of Excitonic Valley Coherence in Monolayer WSe2
• Measurement of the optical dielectric function of transition metal dichalcogenide monolayers: MoS2, MoSe2, WS2 and WSe2
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• Valley-selective optical Stark effect in monolayer WS2
• Valley dynamics probed through charged and neutral exciton emission in monolayer WSe2
• Ultrafast Generation of Pseudo-magnetic Field for Valley Excitons in WSe2 Monolayers
• Exciton Valley Dynamics probed by Kerr Rotation in WSe2 Monolayers
• Excitons in van der Waals heterostructures: The important role of dielectric screening
• Ultrafast Manipulation of Valley Pseudospin
• Probing the influence of dielectric environment on excitons in monolayer WSe2: Insight from high magnetic fields
• Valley-Polarized Exciton-Polaritons in a Monolayer Semiconductor
• Exciton dynamics in atomically thin MoS2: inter-excitonic interaction and broadening kinetics
• Quasiparticle Band Gaps, Excitonic Effects, and Anisotropic Optical Properties of Monolayer Distorted 1-T Diamond-chain Structures
• Gate controlled spin-valley locking of resident carriers in WSe2 monolayers
• Large, valley-exclusive Bloch-Siegert shift in monolayer WS2
• Mutual Photoluminescence Quenching and Photovoltaic Effect in Large-Area Single-Layer MoS2-Polymer Heterojunctions
• Observation of intervalley biexcitonic optical Stark effect in monolayer WS2
• Time-resolved Kerr rotation spectroscopy of valley dynamics in single-layer MoS2

Cited by in corpus (14)

• Roadmap for Photonics with 2D Materials
• Floquet Engineering of Nonequilibrium Valley-Polarized Quantum Anomalous Hall Effect with Tunable Chern Number
• Strong Rashba effect in the localized impurity states of halogen-doped monolayer PtSe2
• Ultrafast valley-selective coherent optical manipulation with excitons in WSe${}_2$ and MoS${}_2$ monolayers
• Exciton-coherence generation through diabatic and adiabatic dynamics of Floquet state
• Room Temperature Terahertz Electroabsorption Modulation by Excitons in Monolayer Transition Metal Dichalcogenides
• Valley Depolarization in Monolayer Transition-Metal Dichalcogenides with Zone-Corner Acoustic Phonons
• Quantum interference between the optical Stark effect and resonant harmonic generation in WS2
• High harmonic generation in monolayer MoS2 controlled by resonant and near-resonant pulses on ultrashort time scales
• Layer-dependent optically-induced spin polarization in InSe
• Semiconductor Bloch equation analysis of optical Stark and Bloch-Siegert shifts in monolayers WSe${}_2$ and MoS${}_2$
• Effects of Floquet Engineering on the Coherent Exciton Dynamics in Monolayer WS${}_2$
• Optical Stark Effect of a Single Defect on TiO2(110) Surface
• Floquet engineering in the presence of optically excited carriers