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Thermal

  • Wednesday 3 
  • 15:40
  • - 16:00 
  • 1402 
  • Talk # 2 
  • Session # 3

Probing phonon transport in diamond nanostructures with NV-based thermometry

Kexin Wu1, Valentin Goblot1,3, Enrico Di Lucente4, Claudio Jaramillo1, Nicola Marzari4, Michele Simoncelli5, Christophe Galland1,3

  • 1- Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
  • 2- PROUD SA, Lausanne, Switzerland
  • 3- Center for Quantum Science and Engineering, EPFL, Lausanne, Switzerland
  • 4- Theory and Simulation of Materials and National Centre for Computational Design and Discovery of Novel Materials, EPFL, Lausanne, Switzerland
  • 5- Department of Applied Physics and Applied Mathematics, Columbia University, New York, USA

Presenting Author:

  • Kexin
  • Wu

kexin.wu@epfl.ch

Heat transport in microstructures and low-dimensional materials exhibits novel physics that transcends the traditional Fourier law. Different non-Fourier heat conduction regimes emerge depending on the relative magnitudes of phonon mean free paths resulting from various scattering events and the material’s characteristic dimensions. The hydrodynamic regime, where heat behaves like a viscous fluid, exists between diffusive and ballistic transport under stringent conditions. Although previously thought to be limited to temperatures below 50 K, hydrodynamic heat transport has been observed in graphite up to 200 K [1]. Notably, theoretical predictions suggest that this behavior could extend to room temperature in diamond, which possesses ultralong phonon mean free paths that favor momentum-conserving scattering as the dominant transport mechanism [2].
By utilizing negatively charged nitrogen-vacancy (NV) centers as precise nanoscale temperature sensors, I will show how we can study heat transport in diamond microstructures with unprecedented spatial and thermal resolution, in a non-invasive manner [3]. Suspended diamond nano-microstructures with arbitrary geometries, ranging in size from 50 nm to tens of microns, were created to function as customizable heat transport channels. Heat is generated through laser-absorbing metal patches placed at the apex of these structures. At the same time, a second laser beam probes the temperature gradient via optically detected magnetic resonance (ODMR) with diffraction-limited resolution [3].
We also present ongoing work aimed at specifically investigating the heat rectification effect driven by hydrodynamic phonon transport in paired nozzle and diffuser geometries. We report measurements of the temperature profiles and rectification factors of structures with varying parameters to experimentally examine diamond thermal rectification devices within the hydrodynamic phonon transport regime.

1. Z. Ding, et al., Nat. Commun 13, (2022), 285
2. M. Simoncelli, et al., Phys. Rev. X 10, (2020), 011019
3. V. Goblot, et al., arXiv:2411.04065, (2024)