Unconventional scaling of the superfluid density with the critical temperature in transition metal dichalcogenides.
Sci Adv
; 5(11): eaav8465, 2019 11.
Article
em En
| MEDLINE
| ID: mdl-31819897
ABSTRACT
We report on muon spin rotation experiments probing the magnetic penetration depth λ(T) in the layered superconductors in 2H-NbSe2 and 4H-NbSe2. The current results, along with our earlier findings on 1T'-MoTe2 (Guguchia et al.), demonstrate that the superfluid density scales linearly with T c in the three transition metal dichalcogenide superconductors. Upon increasing pressure, we observe a substantial increase of the superfluid density in 2H-NbSe2, which we find to correlate with T c. The correlation deviates from the abovementioned linear trend. A similar deviation from the Uemura line was also observed in previous pressure studies of optimally doped cuprates. This correlation between the superfluid density and T c is considered a hallmark feature of unconventional superconductivity. Here, we show that this correlation is an intrinsic property of the superconductivity in transition metal dichalcogenides, whereas the ratio T c/T F is approximately a factor of 20 lower than the ratio observed in hole-doped cuprates. We, furthermore, find that the values of the superconducting gaps are insensitive to the suppression of the charge density wave state.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
Sci Adv
Ano de publicação:
2019
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Article
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