Inhibition of the photoinduced structural phase transition in the excitonic insulator Ta${}_2$NiSe${}_5$

Abstract

Femtosecond time-resolved mid-infrared reflectivity is used to investigate the electron and phonon dynamics occurring at the direct band gap of the excitonic insulator Ta${}_2$NiSe${}_5$ below the critical temperature of its structural phase transition. We find that the phonon dynamics show a strong coupling to the excitation of free carriers at the Γ point of the Brillouin zone. The optical response saturates at a critical excitation fluence $F_C=0.30\pm 0.08$~mJ/cm${}^2$ due to optical absorption saturation. This limits the optical excitation density in Ta${}_2$NiSe${}_5$ so that the system cannot be pumped sufficiently strongly to undergo the structural change to the high-temperature phase. We thereby demonstrate that Ta${}_2$NiSe${}_5$ exhibits a blocking mechanism when pumped in the near-infrared regime, preventing a nonthermal structural phase transition.

References in corpus (15)

• Ultrafast switching to a stable hidden topologically protected quantum state in an electronic crystal
• Instantaneous band gap collapse in photoexcited monoclinic VO${}_2$ due to photocarrier doping
• Ultrafast changes in lattice symmetry probed by coherent phonons
• Non-thermal separation of electronic and structural orders in a persisting charge density wave
• Ultrafast transient generation of spin-densitywave order in the normal state of BaFe2As2 driven by coherent lattice vibrations
• Orthorhombic-to-Monoclinic Phase Transition of Ta2NiSe5 Induced by the Bose-Einstein Condensation of Excitons
• Ultrafast Electronic Band Gap Control in an Excitonic Insulator
• Excitonic Bose-Einstein condensation in Ta2NiSe5 above room temperature
• Giant exciton Fano resonance in quasi-one-dimensional Ta${}_2$NiSe${}_5$
• Single-particle and collective mode couplings associated with 1- and 2-directional electronic ordering in metallic RTe${}_3$ (R = Ho, Dy, Tb)
• Photo-induced enhancement of excitonic order
• Photo-induced gap closure in an excitonic insulator
• Mechanisms of nonthermal destruction of the superconducting state and melting of the charge-density-wave state by femtosecond laser pulses
• Order, criticality and excitations in the extended Falicov-Kimball model
• Fate of the excitonic insulator in the presence of phonons

Cited by in corpus (30)

• Photo-induced semimetallic states realised in electron-hole coupled insulators
• Direct observation of excitonic instability in Ta2NiSe5
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• Imaging the coherent propagation of collective modes in the excitonic insulator candidate Ta${}_2$NiSe${}_5$ at room temperature
• Photoinduced multistage phase transitions in Ta2NiSe5
• Detecting electron-phonon couplings during photo-induced phase transition
• Ultrafast melting and recovery of collective order in the excitonic insulator Ta${}_2$NiSe${}_5$
• Orthorhombic-to-monoclinic transition in Ta${}_2$NiSe${}_5$ due to a zone-center optical phonon instability
• Phononic soft mode and strong electronic background behavior across the structural phase transition in the excitonic insulator Ta${}_2$NiSe${}_5$ (with Erratum)
• Photo-induced phase transition and associated time scales in the excitonic insulator Ta${}_2$NiSe${}_5$
• Role of electron-phonon coupling in excitonic insulator candidate Ta2NiSe5
• A New Era of Excitonic Insulators
• Nonequilibrium dynamics in the pump-probe spectroscopy of excitonic insulators
• Nonlinear spectroscopy of collective modes in excitonic insulator
• Disentangling lattice and electronic instabilities in the excitonic insulator candidate Ta${}_2$NiSe${}_5$ by nonequilibrium spectroscopy
• Unveiling the underlying interactions in Ta2NiSe5 from photo-induced lifetime change
• Signatures of ultrafast reversal of excitonic order in Ta${}_2$NiSe${}_5$
• Terahertz parametric amplification as a reporter of exciton condensate dynamics
• Photoinduced electron-electron pairing in the extended Falicov-Kimball model
• Ultrafast charge carrier and exciton dynamics in an excitonic insulator probed by time-resolved photoemission spectroscopy
• Tunneling-tip-induced collapse of the charge gap in the excitonic insulator Ta${}_2$NiSe${}_5$
• Evolution of the electronic structure in Ta${}_2$NiSe${}_5$ across the structural transition revealed by resonant inelastic x-ray scattering
• Pressure suppression of the excitonic insulator state in Ta2NiSe5 observed by optical conductivity
• Theory of time-crystalline behaviour mediated by phonon squeezing in Ta2NiSe5
• Third-harmonic generation in excitonic insulators
• Collective modes and Raman response in Ta${}_2$NiSe${}_5$
• FFLO Superconductivity Mediated by Excitonic Fluctuation in Semimetallic Ta${}_2$NiSe${}_5$
• Anomalous phonon Grüneisen parameters in semiconductor Ta${}_2$NiS${}_5$
• Role of interlayer shear phonons on lattice symmetry switching in the transition metal dichalcogenide WTe${}_2$
• Long-lived relaxation channel and exciton-phonon coupling in Ta2NiSe5 via non-degenerate pump-probe spectroscopy