title: Evidence for Photoinduced Insulator-to-Metal transition in B-phase vanadium dioxide.
abstract: Ultrafast optical studies have been performed on epitaxial films of the novel B-phase of vanadium dioxide using temperature-dependent optical pump-probe technique. Signature of temperature-driven metal-to-insulator transition was distinctly observed in the ultrafast dynamics - the insulating phase showed two characteristic electronic relaxation times while the metallic phase showed only one. Beyond a threshold value of the pump fluence, the insulating state collapses into a 'metallic-like' phase which can be further subdivided into two regimes according to the lengths of the fast characteristic time. The first regime can be explained by lattice heating due to the optical pump; the other cannot be accounted by simple lattice heating effects alone, and thus offers evidence for a true photoinduced phase transition.
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: James
authors.initials: J
authors.lastname: Lourembam
authors.affiliation: NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore.|Department of Physics, National University of Singapore, Singapore 117542, Singapore.
authors.forename: Amar
authors.initials: A
authors.lastname: Srivastava
authors.affiliation: Nanoscience and Nanotechnology Graduate Program, King Mongkut's University of Technology Thonburi (KMUTT), 10140, Thailand.|Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), 10140, Thailand.|Theoretical and Computational Science Center (TaCS), Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), 10140, Thailand.
authors.forename: Chan
authors.initials: C
authors.lastname: La-O-Vorakiat
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Liang
authors.initials: L
authors.lastname: Cheng
authors.affiliation: NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore.|Department of Physics, National University of Singapore, Singapore 117542, Singapore.|Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore.|Department of Materials Sciences and Engineering, National University of Singapore, Singapore 117576, Singapore.|Department of Integrated Sciences and Engineering, National University of Singapore, Singapore 117456, Singapore.
authors.forename: T
authors.initials: T
authors.lastname: Venkatesan
authors.affiliation: Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore.
authors.forename: Elbert E M
authors.initials: EE
authors.lastname: Chia