Electron-phonon interaction and point contact enhanced superconductivity in trigonal PtBi2

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • D. L. Bashlakov - , NASU - B. Verkin Institute for Low Temperature Physics and Engineering (Author)
  • O. E. Kvitnitskaya - , NASU - B. Verkin Institute for Low Temperature Physics and Engineering (Author)
  • G. Shipunov - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • S. Aswartham - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • O. D. Feya - , Leibniz Institute for Solid State and Materials Research Dresden, Kyiv Academic University (Author)
  • D. V. Efremov - , Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • B. Büchner - , Chair of Experimental Solid State Physics, Leibniz Institute for Solid State and Materials Research Dresden (Author)
  • Yu G. Naidyuk - , NASU - B. Verkin Institute for Low Temperature Physics and Engineering (Author)

Abstract

PtBi2 is a Weyl semimetal, which demonstrates superconductivity with low critical temperature Tc ∼0.6 K in the bulk. Here, we report our study of electron-phonon interaction (EPI) in trigonal PtBi2 by the Yanson point- contact (PC) spectroscopy and present the observation of PC enhanced superconductivity. We show that the Yanson's PC spectra display a broad maximum around 15 meV, indicating, apparently, EPI mechanism of Cooper pairing in PtBi2. Moreover, we discovered a substantial increase of Tc up to ∼3.5 K in PCs. The observed Tc is suf-ficiently higher than the bulk value, as well as detected at hydrostatic pressure. We calculated the phonon density of states and Eliashberg EPI function in PtBi2 within the framework of the density functional theory. A comparison of experimental data with theoretical calculations showed acceptable agreement. The theoretical Tc is 3.5 K, which corresponds to the experimental value.

Details

Original languageEnglish
Pages (from-to)747-754
Number of pages8
JournalLow temperature physics
Volume48
Issue number10
Publication statusPublished - 1 Oct 2022
Peer-reviewedYes

Keywords

ASJC Scopus subject areas