Reproduction of the charge density wave phase diagram in $1T$-${\mathrm{TiSe}}_2$ exposes its excitonic character

Abstract

Recent experiments suggest that excitonic degrees of freedom play an important role in precipitating the charge density wave (CDW) transition in $1T$-${\mathrm{TiSe}}_2$. Through systematic calculations of the electronic and phonon spectrum based on density functional perturbation theory, we show that the predicted critical doping of the CDW phase overshoots the experimental value by 1 order of magnitude. In contrast, an independent self-consistent many-body calculation of the excitonic order parameter and renormalized band structure is able to capture the experimental phase diagram in extremely good qualitative and quantitative agreement. This demonstrates that electron-electron interactions and the excitonic instability arising from direct electron-hole coupling are pivotal to accurately describe the nature of the CDW in this system. This has important implications to understand the emergence of superconductivity within the CDW phase of this and related systems.

References in corpus (24)

• Evidence of Ising pairing in superconducting NbSe${}_2$ atomic layers
• Superconductivity in Cu_xTiSe_2
• Evidence for an excitonic insulator phase in 1T-TiSe${}_2$
• Controlling many-body states by the electric-field effect in a two-dimensional material
• Signatures of exciton condensation in a transition metal dichalcogenide
• Charge density wave origin of cuprate checkerboard visualized by scanning tunneling microscopy
• Extended Phonon Collapse and the Origin of the Charge-Density-Wave in NbSe${}_2$
• Nature of the Quantum Metal in a Two-Dimensional Crystalline Superconductor
• Charge density wave and superconducting dome in TiSe2 from electron-phonon interaction
• Gate tuning of electronic phase transitions in two-dimensional NbSe${}_2$
• Spontaneous exciton condensation in 1T-TiSe2: a BCS-like approach
• Electron-Phonon Coupling and the Soft Phonon Mode in TiSe${}_2$
• Exciton condensation driving the periodic lattice distortion of 1T-TiSe2
• Strong anharmonicity induces quantum melting of charge density wave in 2H-NbSe$\_2$ under pressure
• Observation of a Charge Density Wave Incommensuration Near the Superconducting Dome in CuxTiSe2
• Temperature dependent photoemission on 1T-TiSe2: Interpretation within the exciton condensate phase model
• Evolution of the Electronic Structure of 1T-CuxTiSe2
• Critical role of the exchange interaction for the electronic structure and charge-density-wave formation in TiSe2
• Stable charge density wave phase in a 1T-TiSe${}_2$ monolayer
• Impact of Electron-Hole Correlations on the 1T-TiSe2 Electronic Structure
• Chiral charge order in 1$T$-TiSe${}_2$: importance of lattice degrees of freedom
• An Alternative Interpretation of Recent ARPES Measurements on TiSe2
• Discovery of unconventional charge density wave at the surface of K0.9Mo6O17
• Charge Density Waves and the Hidden Nesting of Purple Bronze K${}_{0.9}$Mo${}_6$O${}_{17}$

Cited by in corpus (33)

• Observation of Unconventional Charge Density Wave without Acoustic Phonon Anomaly in Kagome Superconductors AV3Sb5 (A=Rb,Cs)
• Ultrafast charge ordering by self-amplified exciton-phonon dynamics in TiSe${}_2$
• Weak Dimensionality Dependence and Dominant Role of Ionic Fluctuations in the Charge-Density-Wave Transition of NbSe${}_2$
• Collective Modes in Excitonic Insulators: Effects of Electron-Phonon Coupling and Signatures in Optical Response
• Heterobilayers of 2D materials as a platform for excitonic superfluidity
• Tunable spin polarization and electronic structure of bottom-up synthesized MoSi${}_2$N${}_4$ materials
• Evidences for the exciton gas phase and its condensation in monolayer 1T-ZrTe2
• Semimetal-to-semiconductor transition and charge-density-wave melting in $1T$-TiSe${}_{2-x}$S${}_x$ single crystals
• Ab initio phonon self-energies and fluctuation diagnostics of phonon anomalies: Lattice instabilities from Dirac pseudospin physics in transition metal dichalcogenides
• Discommensuration-enhanced superconductivity in the charge density wave phases of transition-metal dichalcogenides
• A New Era of Excitonic Insulators
• Topological excitonic corner states and nodal phase in bilayer quantum spin Hall insulators
• Charge Density Wave Hampers Exciton Condensation in 1T-TiSe${}_2$
• Structurally assisted melting of excitonic correlations in 1T-TiSe2
• Phase Separation in the Vicinity of Fermi Surface Hot Spots
• Topological charge pumping in excitonic insulators
• Excitonic insulator emerging from semiconducting normal state in $1T$-TiSe${}_2$
• Tightly bound excitons in two-dimensional semiconductors with a flat valence band
• Electron correlations rule the phonon-driven instability in single layer TiSe${}_2$
• Revealing the Charge Density Wave Proximity Effect in Graphene on 1T-TaS${}_2$
• Aspects of symmetry and topology in the charge density wave phase of 1T-TiSe2
• Mapping the dispersion of the occupied and unoccupied band structure in photoexcited 1T-TiSe${}_2$
• Carrier-Density Control of the Quantum-Confined 1$T$-TiSe${}_2$ Charge-Density-Wave
• Topological Interlayer Superconductivity in a van der Waals Heterostructure
• Impact ionization dynamics in small band-gap 2D materials from a coherent phonon mechanism
• Topological theory of inversion-breaking charge-density-wave monolayer 1\textit{T}-TiSe${}_2$
• Transitions in Xenes between excitonic, topological and trivial insulator phases: influence of screening, band dispersion and external electric field
• Interplay between the charge density wave phase and a pseudogap under antiferromagnetic correlations
• Optical amplification in a CDW-phase of a quasi-two dimensional material
• Multiband Quantum Materials
• Doping-induced nematic and stripe orders within the charge density wave state of TiSe${}_2$
• Excitons and Optical Response in Excitonic Insulator Candidate TiSe${}_2$
• Metal-to-insulator transition in Pt-doped TiSe${}_2$ driven by emergent network of narrow transport channels