title: Ultrafast electronic and structural response of monolayer MoS2 under intense photoexcitation conditions.
abstract: We report on the dynamical response of single layer transition metal dichalcogenide MoS2 to intense above-bandgap photoexcitation using the nonlinear-optical second order susceptibility as a direct probe of the electronic and structural dynamics. Excitation conditions corresponding to the order of one electron-hole pair per unit cell generate unexpected increases in the second harmonic from monolayer films, occurring on few picosecond time-scales. These large amplitude changes recover on tens of picosecond time-scales and are reversible at megahertz repetition rates with no photoinduced change in lattice symmetry observed despite the extreme excitation conditions.
authors.affiliation: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors.forename: Ehren M
authors.initials: EM
authors.lastname: Mannebach
authors.forename: Karel-Alexander N
authors.initials: KA
authors.lastname: Duerloo
authors.forename: Lenson A
authors.initials: LA
authors.lastname: Pellouchoud
authors.forename: Meng-Ju
authors.initials: MJ
authors.lastname: Sher
authors.forename: Sanghee
authors.initials: S
authors.lastname: Nah
authors.forename: Yi-Hong
authors.initials: YH
authors.lastname: Kuo
authors.forename: Yifei
authors.initials: Y
authors.lastname: Yu
authors.forename: Ann F
authors.initials: AF
authors.lastname: Marshall
authors.forename: Linyou
authors.initials: L
authors.lastname: Cao
authors.forename: Evan J
authors.initials: EJ
authors.lastname: Reed
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Lindenberg
keywords: MoS2; femtosecond; molybdenum disulfide; monolayer; second harmonic generation; ultrafast dynamics