中国物理B ›› 2023, Vol. 32 ›› Issue (8): 86801-086801.doi: 10.1088/1674-1056/acd2b4

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Quantum tunneling in the surface diffusion of single hydrogen atoms on Cu(001)

Xiaofan Yu(于小凡)1,2, Yangwu Tong(童洋武)1,2, and Yong Yang(杨勇)1,2,†   

  1. 1. Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China;
    2. Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China
  • 收稿日期:2023-03-08 修回日期:2023-04-21 接受日期:2023-05-05 发布日期:2023-07-14
  • 通讯作者: Yong Yang E-mail:yyanglab@issp.ac.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China(Grant Nos.11474285 and 12074382).

Quantum tunneling in the surface diffusion of single hydrogen atoms on Cu(001)

Xiaofan Yu(于小凡)1,2, Yangwu Tong(童洋武)1,2, and Yong Yang(杨勇)1,2,†   

  1. 1. Key Laboratory of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China;
    2. Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China
  • Received:2023-03-08 Revised:2023-04-21 Accepted:2023-05-05 Published:2023-07-14
  • Contact: Yong Yang E-mail:yyanglab@issp.ac.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China(Grant Nos.11474285 and 12074382).

摘要: The adsorption and diffusion of hydrogen atoms on Cu(001) are studied using first-principles calculations. By taking into account the contribution of zero-point energy (ZPE), the originally identical barriers are shown to be different for H and D, which are respectively calculated to be ~ 158 meV and ~ 139 meV in height. Using the transfer matrix method (TMM), we are able to calculate the accurate probability of transmission across the barriers. The crucial role of quantum tunneling is clearly demonstrated at low-temperature region. By introducing a temperature-dependent attempting frequency prefactor, the rate constants and diffusion coefficients are calculated. The results are in agreement with the experimental measurements at temperatures from ~ 50 K to 80 K.

关键词: H/Cu(001), first-principles calculations, quantum tunneling, diffusion coefficients

Abstract: The adsorption and diffusion of hydrogen atoms on Cu(001) are studied using first-principles calculations. By taking into account the contribution of zero-point energy (ZPE), the originally identical barriers are shown to be different for H and D, which are respectively calculated to be ~ 158 meV and ~ 139 meV in height. Using the transfer matrix method (TMM), we are able to calculate the accurate probability of transmission across the barriers. The crucial role of quantum tunneling is clearly demonstrated at low-temperature region. By introducing a temperature-dependent attempting frequency prefactor, the rate constants and diffusion coefficients are calculated. The results are in agreement with the experimental measurements at temperatures from ~ 50 K to 80 K.

Key words: H/Cu(001), first-principles calculations, quantum tunneling, diffusion coefficients

中图分类号:  (Chemisorption/physisorption: adsorbates on surfaces)

  • 68.43.-h
82.65.+r (Surface and interface chemistry; heterogeneous catalysis at surfaces) 66.35.+a (Quantum tunneling of defects)