Electron-phonon-dominated charge-density-wave fluctuations in TiSe${}_2$ accessed by ultrafast nonequilibrium dynamics

Abstract

The complex phase diagram of 1T-TiSe2 consists of a charge density wave (CDW) below 200 K, and CDW fluctuations of still unknown origin at higher temperatures. Here, we use time-resolved extreme ultraviolet momentum microscopy and density functional perturbation theory to uncover the formation mechanism of CDW fluctuations and their spectral features at 295 K. We investigated the transient dynamics of fluctuations upon nonresonant ultrafast photoexcitation, and directly correlate it with the CDW soft-phonon hardening. Surprisingly, our results show that the coherent amplitude mode modulating ultrafast CDW recovery persists above TCDW, and reveal that CDW fluctuations are dominated by the electron-phonon interaction rather than excitonic correlations as commonly believed. Our findings on these microscopic CDW fluctuations clarify the complex interplay between electronic and lattice degrees of freedom at elevated temperatures and, therefore, could be useful in understanding the nature of the CDW phase transition in 1T-TiSe2 and similar quantum materials.

References in corpus (44)

• Phonons and related properties of extended systems from density-functional perturbation theory
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Optimized norm-conserving Vanderbilt pseudopotentials
• Maximally localized Wannier functions: Theory and applications
• The PseudoDojo: Training and grading a 85 element optimized norm-conserving pseudopotential table
• Electron-phonon interactions from first principles
• Superconductivity in Cu_xTiSe_2
• Evidence for an excitonic insulator phase in 1T-TiSe${}_2$
• Signatures of exciton condensation in a transition metal dichalcogenide
• Non-thermal separation of electronic and structural orders in a persisting charge density wave
• Two energy gaps and Fermi surface 'arcs' in NbSe2
• Pseudogap and charge density waves in two dimensions
• Dynamical charge density fluctuations pervading the phase diagram of a Cu-based high-Tc superconductor
• Chiral charge-density-waves
• Spontaneous exciton condensation in 1T-TiSe2: a BCS-like approach
• Pseudogap in High - Temperature Superconductors
• Electron-Phonon Coupling and the Soft Phonon Mode in TiSe${}_2$
• Time- and Angle-Resolved Photoemission Studies of Quantum Materials
• Optical detection and manipulation of spontaneous gyrotropic electronic order in a transition-metal dichalcogenide semimetal
• Temperature dependent photoemission on 1T-TiSe2: Interpretation within the exciton condensate phase model
• Ultrafast charge ordering by self-amplified exciton-phonon dynamics in TiSe${}_2$
• Orbital- and $k_z$-selective hybridisation of Se 4p and Ti 3d states in the charge density wave phase of TiSe${}_2$
• Optical manipulation of electronic dimensionality in a quantum material
• Revealing the role of electrons and phonons in the ultrafast recovery of charge density wave correlations in 1$T$-TiSe${}_2$
• Mechanisms of electron-phonon coupling unraveled in momentum and time: The case of soft-phonons in TiSe${}_2$
• Excitonic and lattice contributions to the charge density wave in 1T-TiSe${}_2$ revealed by a phonon bottleneck
• Impact of Electron-Hole Correlations on the 1T-TiSe2 Electronic Structure
• Charge Density Wave Hampers Exciton Condensation in 1T-TiSe${}_2$
• Dramatic Plasmon Response to the Charge-Density-Wave Gap Development in $1\text{T}-{\mathrm{TiSe}}_2$
• Ultrafast Switching from the Charge Density Wave Phase to a Metastable Metallic State in 1T-TiSe${}_2$
• Symmetry-guided nonrigid registration: the case for distortion correction in multidimensional photoemission spectroscopy
• Phase Separation in the Vicinity of Fermi Surface Hot Spots
• Ultrafast creation of a light induced semimetallic state in strongly excited 1T-TiSe${}_2$
• Electronic structure of two-dimensional hexagonal diselenides: charge density waves and pseudogap behavior
• Scattering dominated high-temperature phase of 1T-TiSe2: an optical conductivity study
• Ultrafast Polarization-Tunable Monochromatic Extreme Ultraviolet Source at High-Repetition-Rate
• Multi-Mode Lens for Momentum Microscopy and XPEEM: Theory
• Lifshitz transition enabling superconducting dome around the quantum critical point in TiSe${}_2$
• Fluctuated lattice-driven charge density wave far above the condensation temperature in kagome superconductor KV${}_3$Sb${}_5$
• Unveiling van Hove singularity modulation and fluctuated charge order in kagome superconductor $\mathrm{Cs}{\mathrm{V}}_3\mathrm{S}{\mathrm{b}}_5$ via time-resolved ARPES
• In-plane anisotropy of charge density wave fluctuations in 1$T$-TiSe${}_2$
• Persistence of charge ordering instability to Coulomb engineering in the excitonic insulator candidate TiSe${}_2$
• Ultrafast melting of charge-density wave fluctuations at room temperature in $1T-TiS{e}_2$ monitored under non-equilibrium conditions
• Multimode Objective Lens for Momentum Microscopy and XPEEM: Experiments

Cited by in corpus (1)

• Emergent surface resonance from charge density wave symmetry breaking in TiSe2