Combined investigation of collective amplitude and phase modes in a quasi-one-dimensional charge-density-wave system over a wide spectral range

Abstract

We investigate experimentally both the amplitude and phase channels of the collective modes in the quasi-1D charge-density-wave (CDW) system, K0.3MoO3, by combining (i) optical impulsive-Raman pump-probe and (ii) terahertz time-domain spectroscopy (THz-TDS), with high resolution and a detailed analysis of the full complex-valued spectra in both cases. This allows an unequivocal assignment of the observed bands to CDW modes across the THz range up to 9 THz. We revise and extend a time-dependent Ginzburg-Landau model to account for the observed temperature dependence of the modes, where the combination of both amplitude and phase modes allows one to robustly determine the bare-phonon and electron-phonon coupling parameters. While the coupling is indeed strongest for the lowest-energy phonon, dropping sharply for the immediately subsequent phonons, it grows back significantly for the higher-energy phonons, demonstrating their important role in driving the CDW formation. We also include a reassessment of our previous analysis of the lowest-lying phase modes, whereby assuming weaker electronic damping for the phase channel results in a qualitative picture more consistent with quantum-mechanical treatments of the collective modes, with a strongly coupled amplitudon and phason as the lowest modes.

References in corpus (17)

• Direct observation of competition between superconductivity and charge density wave order in YBa2Cu3Oy
• CsV${}_3$Sb${}_5$: a ${\mathbb{Z}}_2$ topological kagome metal with a superconducting ground state
• Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure
• Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal
• Evidence for an axionic charge density wave in the Weyl semimetal (TaSe4)2I
• Coherent dynamics of macroscopic electronic order through a symmetry-breaking transition
• Thermodynamic evidence for nematic phase transition at the onset of pseudogap in YBa${}_2$Cu${}_3$O${}_y$
• Disentanglement of the electronic and lattice parts of the order parameter in a 1D Charge Density Wave system probed by femtosecond spectroscopy
• A new collective mode in YBCO observed by time-domain reflectometry
• Unconventional Charge Density Wave Order in the Pnictide Superconductor Ba(Ni${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Amplitude dynamics of charge density wave in LaTe${}_3$: theoretical description of pump-probe experiments
• An Electronic Nematic Liquid in BaNi${}_2$As${}_2$
• Superconductivity and charge-density wave formation in lithium intercalated 2H-LixTaS2
• A Raman study of the Charge-Density-Wave State in A${}_{0.3}$MoO${}_3$ (A = K,Rb)
• Phase-channel dynamics reveal the role of impurities and screening in a quasi-one-dimensional charge-density wave system
• Collective modes in the charge-density wave state of K${}_{0.3}$MoO${}_3$: The role of long-range Coulomb interactions revisited
• AC-Conductivity of Pinned Charge Density Wave Fluctuations in Quasi One-Dimensional Conductors

Cited by in corpus (2)

• Exceptionally Slow, Long Range, and Non-Gaussian Critical Fluctuations Dominate the Charge Density Wave Transition
• Collective modes in the charge-density wave state of K${}_{0.3}$MoO${}_3$: The role of long-range Coulomb interactions revisited