Charge Density Wave Hampers Exciton Condensation in 1T-TiSe${}_2$

Abstract

The Bose-Einstein condensation of excitons continues to garner immense attention as a prototypical example for observing emergent properties from many-body quantum effects. In particular, Titanium Diselenide (TiSe${}_2$) is a promising candidate for realizing exciton condensation and was experimentally observed only very recently. Surprisingly, the condensate was experimentally characterized by a soft plasmon mode that only exists near the transition temperature, $T_c$, of the charge density wave (CDW). Here, we characterize and analyze the experimental spectra using linear-response time-dependent density functional theory and find that the soft mode can be attributed to interband electronic transitions. At the CDW state below $T_c$, the periodic lattice distortions hamper the spontaneous formation of the exciton by introducing a CDW gap. The band gap raises the soft mode and merges it into the regular plasmon. Our surprising results contradict previous simplistic analytical models commonly used in the scientific literature. In addition, we find that a finite electronic temperature, $T_e$, introduces a dissipation channel and prevents the condensation above $T_c$. The combined effect of the CDW and $T_e$ explains the fragile temperature-dependence of the exciton condensation. Taken together, our work provides the first \textit{ab initio} atomic-level framework for rationalizing recent experiments and further manipulating exciton condensates in TiSe${}_2$.

References in corpus (72)

• Phonons and related properties of extended systems from density-functional perturbation theory
• A real-space grid implementation of the Projector Augmented Wave method
• Electron-phonon interactions from first principles
• Resonant Inelastic X-ray Scattering Studies of Elementary Excitations
• EPW: Electron-phonon coupling, transport and superconducting properties using maximally localized Wannier functions
• Superconductivity in Cu_xTiSe_2
• Bose-Einstein Condensation of Excitons in Bilayer Electron Systems
• Quantised Vortices in an Exciton-Polariton Fluid
• Realization of Bose-Einstein condensation of dilute magnons in TlCuCl${}_3$
• Excitations in a non-equilibrium Bose-Einstein condensate of exciton-polaritons
• Evidence for an excitonic insulator phase in 1T-TiSe${}_2$
• Current-dependent exchange-correlation potential for dynamical linear response theory
• Signatures of exciton condensation in a transition metal dichalcogenide
• Unfolding first-principles band structures
• Optoelectronic and Excitonic Properties of Oligoacenes: Substantial Improvements from Range-Separated Time-Dependent Density Functional Theory
• Non-Empirically Tuned Range-Separated DFT Accurately Predicts Both Fundamental and Excitation Gaps in DNA and RNA Nucleobases
• Time-dependent density functional theory beyond the adiabatic local density approximation
• Charge density wave and superconducting dome in TiSe2 from electron-phonon interaction
• Strong charge-transfer excitonic effects and Bose-Einstein exciton-condensate in graphane
• Polariton dynamics and Bose-Einstein condensation in semiconductor microcavities
• Bootstrap approximation for the exchange-correlation kernel of time-dependent density functional theory
• Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
• Coumarin Dyes for Dye-Sensitized Solar Cells - A Long-Range-Corrected Density Functional Study
• Semimetal to semimetal charge density wave transition in 1T-TiSe${}_2$
• Absorption and Fluorescence Properties of Oligothiophene Biomarkers from Long-Range-Corrected Time-Dependent Density Functional Theory
• Spontaneous exciton condensation in 1T-TiSe2: a BCS-like approach
• Bose-Einstein condensation in semiconductors: the key role of dark excitons
• Electron-Phonon Coupling and the Soft Phonon Mode in TiSe${}_2$
• Bose-Einstein Condensation of Magnons in Cs2CuCl4
• Optoelectronic Properties of Carbon Nanorings: Excitonic Effects from Time-Dependent Density Functional Theory
• Exciton condensation driving the periodic lattice distortion of 1T-TiSe2
• Time-dependent density-functional theory beyond the adiabatic approximation: insights from a two-electron model system
• Order parameter dynamics of a Bose-Einstein condensate of exciton-polaritons in semiconductor microcavities
• Influence of domain walls in the incommensurate charge density wave state of Cu intercalated 1$T$-TiSe${}_2$
• Observation of a Charge Density Wave Incommensuration Near the Superconducting Dome in CuxTiSe2
• Molecular beam epitaxy growth and scanning tunneling microscopy study of TiSe${}_2$ ultrathin films
• Verification of first-principles codes: comparison of total energies, phonon frequencies, electron-phonon coupling and zero-point motion correction to the gap between ABINIT and QE/Yambo
• Temperature dependent photoemission on 1T-TiSe2: Interpretation within the exciton condensate phase model
• Bose-Einstein Condensation of Excitons in Cu${}_2$O: Progress Over Thirty Years
• Quantum and classical mode softening near the charge-density-wave/superconductor transition of Cu${}_x$TiSe${}_2$: Raman spectroscopic studies
• Real-Time Quantum Dynamics of Long-Range Electronic Excitation Transfer in Plasmonic Nanoantennas
• The Importance of Short- and Long-Range Exchange on Various Excited State Properties of DNA Monomers, Stacked Complexes, and Watson-Crick Pairs
• Time-dependent current density functional theory for the linear response of weakly disordered systems
• Manipulating charge-density-wave in monolayer $1T$-TiSe${}_2$ by strain and charge doping: A first-principles investigation
• Reproduction of the charge density wave phase diagram in $1T$-${\mathrm{TiSe}}_2$ exposes its excitonic character
• Time-dependent Kohn-Sham theory with memory
• Stripe and short range order in the charge density wave of 1T-Cu${}_x$TiSe${}_2$
• Chiral charge order in 1$T$-TiSe${}_2$: importance of lattice degrees of freedom
• Impact of Electron-Hole Correlations on the 1T-TiSe2 Electronic Structure
• Short-range phase coherence and origin of the 1T-TiSe2 charge density wave
• An Alternative Interpretation of Recent ARPES Measurements on TiSe2
• Probing Bose-Einstein Condensation of Excitons with Electromagnetic Radiation
• Exciton-phonon cooperative mechanism of the triple-$q$ charge-density-wave and antiferroelectric electron polarization in TiSe${}_2$
• Superconductivity at 2.3 K in the misfit compound (PbSe)1.16(TiSe2)2
• Half Excitonic Insulator: A Single-Spin Bose-Einstein Condensate
• Superconducting dome in MoS2 and TiSe2 generated by quasiparticle-phonon coupling
• Realizing intrinsic excitonic insulator by decoupling exciton binding energy from the minimum band gap
• Electronic correlations stabilizing time-reversal broken chiral superconductivity in single-trilayer TiSe${}_2$
• Charge-density wave induced by combined electron-electron and electron-phonon interactions in 1$T$-TiSe${}_2$: A variational Monte Carlo study
• Local Real-Space View of the Achiral 1$T$-TiSe${}_2$ 2 $\times$ 2 $\times$ 2 Charge Density Wave
• Fully parameter-free calculation of optical spectra for insulators, semiconductors and metals from a simple polarization functional
• Auger decay, Spin-exchange, and their connection to Bose-Einstein condensation of excitons in Cu_2O
• Preformed Excitons, Orbital Selectivity, and Charge-Density-Wave Order in 1T-TiSe_2
• Excitonic effects in two-dimensional TiSe${}_2$ from hybrid density functional theory
• First-principles study of superconductivity in 2D and 3D forms of PbTiSe${}_2$: Suppressed charge density wave in 1\emph{T}-TiSe${}_2$
• Charge Transfer Effects in Naturally Occurring van der Waals Heterostructures (PbSe)1.16(TiSe2)m (m=1, 2)
• Heat Capacity of Single Crystal CuxTiSe2 Superconductors
• Collective intersubband transitions in quantum wells: a comparative density-functional study
• Bose-Einstein Condensation of Magnons Pumped by the Bulk Spin Seebeck Effect
• Dirac Cone Pairs in Silicene Induced by Interface Si-Ag Hybridization: A First Principles Effective Band Study
• Emergent superconductivity upon disordering a charge density wave ground state
• Point-contact tunneling spectroscopy measurement of Cu${}_x$TiSe${}_2$: disorder-enhanced Coulomb effects

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• Electron correlations rule the phonon-driven instability in single layer TiSe${}_2$
• Charge Density Wave Activated Excitons in TiSe${}_2$-MoSe${}_2$ Heterostructures
• Identification of a Low Energy Metastable 1$T$-Type Phase for Monolayer VSe2
• Electron-phonon-dominated charge-density-wave fluctuations in TiSe${}_2$ accessed by ultrafast nonequilibrium dynamics
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