Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films

Journal Article · Mon Jan 25 00:00:00 EST 2016 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4940981· OSTI ID:1238054

Chase, T. ^[1]; Trigo, M. ^[2]; Reid, A. H. ^[2]; Li, R. ^[3]; Vecchione, T. ^[3]; Shen, X. ^[3]; Weathersby, S. ^[3]; Coffee, R. ^[3]; Hartmann, N. ^[3]; Reis, D. A. ^[4]; Wang, X. J. ^[3]; Dürr, H. A.  ^[2]

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1. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Department of Applied Physics, Stanford University, Stanford, California 94305, USA
2. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
3. SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
4. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA; Department of Applied Physics, Stanford University, Stanford, California 94305, USA; PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA

We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1238054
• Journal Information: Applied Physics Letters, Vol. 108, Issue 4; ISSN 0003-6951
• Country of Publication: United States
• Language: English