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Unveiling thermal transport mechanisms in alumina laser crystal using machine learning potential

Yan Dai, Zhongwei Zhang*, Jiamin Quan, Wudi Wang, Chenbo Zhang†, Jun Xu, and Jie Chen‡

  • Center for Phononics and Thermal Energy Science, China-EU Joint Lab for Nanophononics, MOE Key Laboratory of Advanced Micro-structured Materials, School of Physics Science and Engineering, Tongji University, Shanghai 200092, People's Republic of China

  • *Contact author: zhongwei@tongji.edu.cn
  • †Contact author: cbzhang@tongji.edu.cn
  • ‡Contact author: jie@tongji.edu.cn
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Phys. Rev. Research 8, 033238 – Published 27 August, 2026

DOI: https://doi.org/10.1103/ld32-gzc3

Abstract

Heat dissipation capability of laser gain media is critical for ensuring the performance and stability of high-power laser systems. However, the thermal transport mechanisms in these materials, particularly in rare-earth ion-doped laser crystals under high-power heating conditions, remain largely elusive. In this study, we employ molecular dynamics simulations combined with a neuroevolution machine learning potential to investigate the effects of temperature and Ce doping on thermal transport in alumina. Our simulations reveal a significant reduction in thermal conductivity under uniform elevated temperatures and finite Ce doping concentrations, providing quantitative insight into thermal transport in Ce-doped Al2O3 under conditions relevant to laser operation. Simulation results demonstrate that elevated temperature causes a broad-spectrum suppression of thermal transport, while Ce doping predominantly affects specific low-frequency acoustic phonon modes and a few optical modes. Further analysis uncovers a mode-selective phonon-dopant scattering mechanism, where resonant and polarization-dependent coupling leads to the selective suppression of distinct phonon modes. This mechanism is in sharp contrast with the conventional understanding of phonon-dopant scattering observed in typical crystals. These findings provide valuable insights into the atomic-level mechanisms governing heat dissipation in alumina laser crystal, thus paving the way for the design of laser materials with optimized thermal properties for high-power applications.

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Phys. Rev. Research 8, 033238– Published 27 August, 2026
  • Received 11 January 2026
  • Accepted 12 August 2026
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