Optimal boson energy for superconductivity in the Holstein model

    •  Lin, C., Wang, B., Teo, K.H., "Optimal boson energy for superconductivity in the Holstein model", Physical Review B, DOI: 10.1103/​PhysRevB.93.224501, Vol. 93, No. 22, July 2016.
      BibTeX TR2016-100 PDF
      • @article{Lin2016jul,
      • author = {Lin, Chungwei and Wang, Bingnan and Teo, Koon Hoo},
      • title = {Optimal boson energy for superconductivity in the Holstein model},
      • journal = {Physical Review B},
      • year = 2016,
      • volume = 93,
      • number = 22,
      • month = jul,
      • doi = {10.1103/PhysRevB.93.224501},
      • url = {}
      • }
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  • Research Area:

    Applied Physics


We examine the superconducting solution in the Holstein model, where the conduction electrons couple to the dispersionless boson fields, using the Migdal-Eliashberg theory and dynamical mean field theory. Although different in numerical values, both methods imply the existence of an optimal boson energy for superconductivity at a given electron-boson coupling. This nonmonotonous behavior can be understood as an interplay between the polaron and superconducting physics, as the electron-boson coupling is the origin of the superconductor, but at the same time traps the conduction electrons making the system more insulating. Our calculation provides a simple explanation of the recent experiment on sulfur hydride, where an optimal pressure for the superconductivity was observed. The validities of both methods are discussed.