title: Dynamic Structural Response and Deformations of Monolayer MoS2 Visualized by Femtosecond Electron Diffraction.
abstract: Two-dimensional materials are subject to intrinsic and dynamic rippling that modulates their optoelectronic and electromechanical properties. Here, we directly visualize the dynamics of these processes within monolayer transition metal dichalcogenide MoS2 using femtosecond electron scattering techniques as a real-time probe with atomic-scale resolution. We show that optical excitation induces large-amplitude in-plane displacements and ultrafast wrinkling of the monolayer on nanometer length-scales, developing on picosecond time-scales. These deformations are associated with several percent peak strains that are fully reversible over tens of millions of cycles. Direct measurements of electron-phonon coupling times and the subsequent interfacial thermal heat flow between the monolayer and substrate are also obtained. These measurements, coupled with first-principles modeling, provide a new understanding of the dynamic structural processes that underlie the functionality of two-dimensional materials and open up new opportunities for ultrafast strain engineering using all-optical methods.
authors: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors: Ehren M
authors: EM
authors: Mannebach
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Renkai
authors: R
authors: Li
authors: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.
authors: Karel-Alexander
authors: KA
authors: Duerloo
authors: Department of Chemistry, Stanford University , Stanford, California 94305, United States.
authors: Clara
authors: C
authors: Nyby
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Peter
authors: P
authors: Zalden
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Theodore
authors: T
authors: Vecchione
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.|Department of Applied Physics, Stanford University , Stanford, California 94305, United States.|PULSE Institute, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Friederike
authors: F
authors: Ernst
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Alexander Hume
authors: AH
authors: Reid
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.|Department of Applied Physics, Stanford University , Stanford, California 94305, United States.
authors: Tyler
authors: T
authors: Chase
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Xiaozhe
authors: X
authors: Shen
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Stephen
authors: S
authors: Weathersby
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Carsten
authors: C
authors: Hast
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Robert
authors: R
authors: Hettel
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Ryan
authors: R
authors: Coffee
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Nick
authors: N
authors: Hartmann
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Alan R
authors: AR
authors: Fry
authors: Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States.
authors: Yifei
authors: Y
authors: Yu
authors: Department of Materials Science and Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States.
authors: Linyou
authors: L
authors: Cao
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.|Department of Applied Physics, Stanford University , Stanford, California 94305, United States.|PULSE Institute, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Tony F
authors: TF
authors: Heinz
authors: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.|PULSE Institute, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Evan J
authors: EJ
authors: Reed
authors: Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Hermann A
authors: HA
authors: Dürr
authors: SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Xijie
authors: X
authors: Wang
authors: Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States.|Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.|PULSE Institute, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States.
authors: Aaron M
authors: AM
authors: Lindenberg
keywords: 2D materials; MoS2; electron diffraction; structural dynamics; ultrafast