Strong electron–phonon interaction establishes correlation between superconducting and charge density wave states in NbSe2

• Published in: Current science (Bangalore) Vol. 114; no. 4; pp. 888 - 891
• Main Authors: Naik, I., Sethy, S.
• Format: Journal Article
• Language: English
• Published: Current Science Association 25-02-2018
• Subjects: RESEARCH COMMUNICATIONS
• ISSN: 0011-3891
• DOI: 10.18520/cs/v114/i04/888-891

Here an analytical expression is proposed for the correlation between superconducting (SC) transition temperature (Tsc) derived by Louie and Cohen and charge density wave (CDW) transition temperature derived by Peierls at strong electron–phonon interaction. This expression was verified by the pressure effect Tsc and Tcdw of 2H-NbSe2 with m ≈ 64.86 and c ≈ 2.24 as best-fitting parameters. From these parameters, phonon energies $\mathrm{h}\sqrt{\langle {\mathrm{\omega }}_{\mathrm{s}\mathrm{c}}^{2}\rangle }\approx 3.8$ meV and ħωcdw ≈ 1.4 meV were calculated for SC and CDW states respectively. It also provides Tcdw very close to the experimental values of 2H- and 4H-NbSe2, regardless of their stacking order and coordination difference.