title: Quantum melting of the charge-density-wave state in 1T-TiSe2.
abstract: We report a Raman scattering study of low-temperature, pressure-induced melting of the charge-density-wave (CDW) phase of 1T-TiSe2. Our measurements reveal that the collapse of the CDW state occurs in three stages: (i) For P<5 kbar, the pressure dependence of the CDW amplitude mode energies and intensities are indicative of a "crystalline" CDW regime; (ii) for 5<P<25 kbar, there is a decrease in the CDW amplitude mode energies and intensities with increasing pressure that suggests a regime in which the CDW softens, and exhibits enhanced fluctuations; and (iii) for P>25 kbar, the absence of amplitude modes reveals a metallic regime in which the CDW has melted.
authors.affiliation: Department of Physics and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Snow
authors.forename: J F
authors.initials: JF
authors.lastname: Karpus
authors.forename: S L
authors.initials: SL
authors.lastname: Cooper
authors.forename: T E
authors.initials: TE
authors.lastname: Kidd
authors.forename: T-C
authors.initials: TC
authors.lastname: Chiang