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New regimes of nanoscale thermal transport from nanostructured heat sources on diamond probed using coherent EUV beams

ORAL

Abstract

Nanostructured materials make it possible to engineer properties that are unattainable using conventional bulk materials, with applications in next-generation energy efficient devices. However, macroscopic, diffusive transport models break down at length scales comparable to a material’s dominant phonon mean free path. Moreover, there are few, if any, characterization techniques that can probe functional nanosystems. Here we use short wavelength (~30nm), ultrafast pulse (~10fs) extreme ultraviolet (EUV) beams to nondestructively probe nanoscale thermal transport in diamond. We first impulsively heat nickel nano-gratings fabricated on the diamond sample with an infrared pump laser and then extract thermal conductivity by monitoring surface relaxation with a time-delayed EUV probe. Diamond is an ideal candidate for validating emergent transport behaviors because its long phonon mean free path causes non-diffusive effects to appear at larger length scales. We compare our results to an advanced hydrodynamic transport model to isolate the contribution of viscous resistivity directly underneath the nanoheaters to thermal transport. Finally, we gain insight into non-diffusive cooling processes by examining the individual diffracted orders in the scattered EUV probe beam.

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Presenters

  • Brendan McBennett

    STROBE and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST

Authors

  • Brendan McBennett

    STROBE and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST

  • Joshua Knobloch

    STROBE and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST, University of Colorado, Boulder

  • Begoña Abad

    STROBE and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST

  • Travis D Frazer

    STROBE and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST

  • Albert Beardo

    Departament de Física, Universitat Autònoma de Barcelona

  • Lluc Sendra

    Departament de Física, Universitat Autònoma de Barcelona

  • Juan Camacho

    Departament de Física, Universitat Autònoma de Barcelona

  • Javier Bafaluy

    Departament de Física, Universitat Autònoma de Barcelona

  • Weilun Chao

    Center for X-Ray Optics, Lawrence Berkeley National Laboratory

  • Roger Wirth Falcone

    Department of Physics, University of California, Berkeley, University of California Berkeley, Advanced Light Source, Lawrence Berkeley National Laboratory

  • Jorge Hernández-Charpak

    STROBE and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST

  • Henry Kapteyn

    JILA, University of Colorado Boulder, Department of Physics and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado, Boulder, JILA and Department of Physics, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST, Physics, JILA/University of Colorado Boulder, JILA, University of Colorado, Boulder, Physics and JILA, CU Boulder, JILA, University of Colorado, Boulder

  • Xavier Alvarez

    Departament de Física, Universitat Autònoma de Barcelona

  • Margaret Murnane

    JILA, University of Colorado Boulder, Department of Physics and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado, Boulder, STROBE and JILA, University of Colorado and NIST, JILA, University of Colorado, Boulder, Physics and JILA, CU Boulder, University of Colorado, JILA, University of Colorado, Boulder