Strong Coupling of Coherent Phonons to Excitons in Semiconducting Monolayer MoTe${}_2$

Abstract

The coupling of the electron system to lattice vibrations and their time-dependent control and detection provides unique insight into the non-equilibrium physics of semiconductors. Here, we investigate the ultrafast transient response of semiconducting monolayer 2$H$-MoTe${}_2$ encapsulated with $h$BN using broadband optical pump-probe microscopy. The sub-40-fs pump pulse triggers extremely intense and long-lived coherent oscillations in the spectral region of the A' and B' exciton resonances, up to $\sim$20% of the maximum transient signal, due to the displacive excitation of the out-of-plane $A_{1g}$ phonon. Ab-initio calculations reveal a dramatic rearrangement of the optical absorption of monolayer MoTe${}_2$ induced by an out-of-plane stretching and compression of the crystal lattice, consistent with an $A_{1g}$-type oscillation. Our results highlight the extreme sensitivity of the optical properties of monolayer TMDs to small structural modifications and their manipulation with light.

arXiv comment27 pages, 4 figures, supporting information

References in corpus (25)

• Emerging Device Applications for Semiconducting Two-Dimensional Transition Metal Dichalcogenides
• Superconductivity in Weyl Semimetal Candidate MoTe2
• Excitonic linewidth and coherence lifetime in monolayer transition metal dichalcogenides
• Indirect-to-direct band-gap crossover in few-layer MoTe${}_2$
• Photo-Induced Bandgap Renormalization Governs the Ultrafast Response of Single-Layer MoS2
• Field-Effect Transistors Based on Few-Layered alpha-MoTe_2
• First-principles method for electron-phonon coupling and electron mobility: Applications to 2D materials
• Real-Time Observation of Exciton-Phonon Coupling Dynamics in Self-Assembled Hybrid Perovskite Quantum Wells
• Non-thermal separation of electronic and structural orders in a persisting charge density wave
• Coupled Ferroelectricity and Superconductivity in Bilayer $T_d$-MoTe${}_2$
• Electron-Phonon Coupling in High-Temperature Cuprate Superconductors Determined from Electron Relaxation Rates
• Contact Engineering High Performance n-Type MoTe2 Transistors
• Unified description of the optical phonon modes in $N$-layer MoTe${}_2$
• Ab initio calculations of ultra-short carrier dynamics in 2D materials: valley depolarization in single-layer WSe${}_2$
• Strongly coupled coherent phonons in single-layer MoS${}_2$
• Magneto-optical response of chromium trihalide monolayers: chemical trends
• Excitonic and lattice contributions to the charge density wave in 1T-TiSe${}_2$ revealed by a phonon bottleneck
• Nonequilibrium Charge-Density-Wave Order Beyond the Thermal Limit
• Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO2 Nanoparticles
• Polarization-Controlled Coherent Phonon Generation in Acousto-Plasmonic Metasurfaces
• Coherent phonon induced optical modulation in semiconductors at terahertz frequencies
• Ultrafast coherent interlayer phonon dynamics in atomically thin layers of MnBi2Te4
• Photoinduced coherent modulation of an excitonic resonance via coupling with coherent optical phonons
• Spectrally resolving the phase and amplitude of coherent phonons in the charge density wave state of 1$T$-TaSe${}_2$
• Polarization-resolved broadband time-resolved optical spectroscopy for complex materials: application to the case of MoTe${}_2$ polytypes

Cited by in corpus (7)

• Strain-induced activation of chiral-phonon emission in monolayer WS${}_2$
• Theory of coherent phonons coupled to excitons
• Slow Dephasing of Coherent Optical Phonons in Two-dimensional Lead Organic Chalcogenides
• Coherent Modulation of Two-Dimensional Moiré States with On-Chip THz Waves
• Effect of photoinduced screening on the spectroscopic signature of exciton-phonon coupling
• Anomalous amplitude mode dynamics below the expected charge-density-wave transition in 1$T$-VSe${}_2$
• Excitonic effects in the photocarriers dynamics of two-dimensional materials