Evidence of ballistic thermal transport in lithium niobate at room temperature

R. A. Pulavarthy, M. A. Haque

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


In ballistic transport, heat carriers such as phonons travel through the solid without any scattering or interaction. Therefore, there is no temperature gradient in the solid, suggesting zero thermal conductivity by Fourier's law. Ballistic transport is typically seen in high purity crystals at either temperatures below ~ 10 K, or physical size below ~ 100 nm, where the mean free path of the carrier is larger than the solid itself. In this letter, we show evidence of ballistic transport at room temperature in lithium niobate wafers in the in-plane and cross-plane directions under both steady state and high frequency heating that are monitored using both infrared and resistance thermometry. We report phonon mean free path in lithium niobate around 425 μm, which is about 50 times higher than the largest phonon mean free path in the literature at room temperature.

Original languageEnglish (US)
Pages (from-to)28-33
Number of pages6
JournalInternational Communications in Heat and Mass Transfer
StatePublished - Feb 1 2017

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics
  • Chemical Engineering(all)
  • Condensed Matter Physics


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