Abstract
Conventional electron–phonon coupling induces either odd (triplet) or even (singlet) pairing states in a time reversal and inversion invariant Dirac semi-metal. In a certain range of the chemical potential μ and parameters characterizing the pairing attraction (effective electron–electron coupling constant λ and the Debye energy TD) the energy of the singlet although always lower, prevails by a very slim margin over the triplet. This means that interactions that are small but discriminate between the spin singlet and the spin triplet determine the nature of the superconducting order there. It is shown that in materials close enough to the Dirac point (μ≲TD) a moderate exchange constant λex<<1 (below Stoner instability to ferromagnetism) stabilizes the odd pairing superconducting state. The 3D quantum critical point at μ=0 of transition to the triplet superconductivity governs the physics of the superconductor.
Original language | English |
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Pages (from-to) | 101-107 |
Number of pages | 7 |
Journal | Journal of Low Temperature Physics |
Volume | 179 |
Issue number | 1-2 |
DOIs | |
State | Published - Apr 2015 |
Bibliographical note
Publisher Copyright:© 2014, Springer Science+Business Media New York.
Funding
Funders | Funder number |
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National Natural Science Foundation of China | 11274018 |
National Science Council Taiwan | 98-2112-M-009-014-MY3 |
Keywords
- Dirac
- Semi-metal
- Superconductivity