title: Monoclinic and correlated metal phase in VO(2) as evidence of the Mott transition: coherent phonon analysis.
abstract: In femtosecond pump-probe measurements, the appearance of coherent phonon oscillations at 4.5 and 6.0 THz indicating the rutile metal phase of VO2 does not occur simultaneously with the first-order metal-insulator transition (MIT) near 68 degrees C. The monoclinic and correlated metal (MCM) phase between the MIT and the structural phase transition (SPT) is generated by a photoassisted hole excitation, which is evidence of the Mott transition. The SPT between the MCM phase and the rutile metal phase occurs due to subsequent Joule heating. The MCM phase can be regarded as an intermediate nonequilibrium state.
authors.affiliation: IT Convergence and Components Research Laboratory, ETRI, Daejeon 305-350, Republic of Korea. htkim@etri.re.kr
authors.forename: Hyun-Tak
authors.initials: HT
authors.lastname: Kim
authors.forename: Yong Wook
authors.initials: YW
authors.lastname: Lee
authors.forename: Bong-Jun
authors.initials: BJ
authors.lastname: Kim
authors.forename: Byung-Gyu
authors.initials: BG
authors.lastname: Chae
authors.forename: Sun Jin
authors.initials: SJ
authors.lastname: Yun
authors.forename: Kwang-Yong
authors.initials: KY
authors.lastname: Kang
authors.forename: Kang-Jeon
authors.initials: KJ
authors.lastname: Han
authors.forename: Ki-Ju
authors.initials: KJ
authors.lastname: Yee
authors.forename: Yong-Sik
authors.initials: YS
authors.lastname: Lim