中国物理B ›› 2017, Vol. 26 ›› Issue (11): 117401-117401.doi: 10.1088/1674-1056/26/11/117401

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Fluctuating specific heat in two-band superconductors

Lei Qiao(乔雷), Cheng Chi(迟诚), Jiangfan Wang(王江帆)   

  1. School of Physics, Peking University, Beijing 100871, China
  • 收稿日期:2017-07-14 修回日期:2017-08-14 出版日期:2017-11-05 发布日期:2017-11-05
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11674007).

Fluctuating specific heat in two-band superconductors

Lei Qiao(乔雷), Cheng Chi(迟诚), Jiangfan Wang(王江帆)   

  1. School of Physics, Peking University, Beijing 100871, China
  • Received:2017-07-14 Revised:2017-08-14 Online:2017-11-05 Published:2017-11-05
  • Contact: Lei Qiao E-mail:leiqiao@pku.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11674007).

摘要:

Theory of thermal fluctuations in two-band superconductors under an essentially homogeneous magnetic field is developed within the framework of the two-band Ginzburg-Landau theory. The fluctuating specific heat is calculated by using the optimized self-consistent perturbation approach and the results are applied to analyze the thermodynamic data of the iron-based superconductors Ba1-xKxFe2As2 with x~0.4, which have been suggested to have a two-band structure by recent experiments. We estimate the fluctuation strength in this material and find that the specific heat is described well with the Ginzburg number Gi=4·10-4. The influence of interband coupling strength is investigated and the result of the two-band Gaussian approximation approach is compared.

关键词: fluctuating specific heat, two-band superconductors, vortex liquid, self-consistent approximation

Abstract:

Theory of thermal fluctuations in two-band superconductors under an essentially homogeneous magnetic field is developed within the framework of the two-band Ginzburg-Landau theory. The fluctuating specific heat is calculated by using the optimized self-consistent perturbation approach and the results are applied to analyze the thermodynamic data of the iron-based superconductors Ba1-xKxFe2As2 with x~0.4, which have been suggested to have a two-band structure by recent experiments. We estimate the fluctuation strength in this material and find that the specific heat is described well with the Ginzburg number Gi=4·10-4. The influence of interband coupling strength is investigated and the result of the two-band Gaussian approximation approach is compared.

Key words: fluctuating specific heat, two-band superconductors, vortex liquid, self-consistent approximation

中图分类号:  (Thermodynamic properties)

  • 74.25.Bt
74.25.Ha (Magnetic properties including vortex structures and related phenomena) 74.40.-n (Fluctuation phenomena) 74.25.Uv (Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses))