Wickramaratne, D., Khmelevskyi, S., Agterberg, D. F., & Mazin, I. I. (2020). Ising Superconductivity and Magnetism in NbSe₂. Physical Review X, 10(4), Article 041003. https://doi.org/10.1103/physrevx.10.041003
E057-15 - Fachbereich Center for Computational Materials Science and Engineering
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Journal:
Physical Review X
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ISSN:
2160-3308
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Date (published):
Dec-2020
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Number of Pages:
13
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Publisher:
AMER PHYSICAL SOC
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Peer reviewed:
Yes
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Keywords:
General Physics and Astronomy; Superconductivity
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Abstract:
Recent studies on superconductivity in NbSe₂ have demonstrated a large anisotropy in the superconducting critical field when the material is reduced to a single monolayer. Motivated by this recent discovery, we use density-functional theory (DFT) calculations to quantitatively address the superconducting properties of bulk and monolayer NbSe₂. We demonstrate that NbSe₂ is close to a ferromagnetic instability, and analyze our results in the context of experimental measurements of the spin susceptibility in NbSe₂. We show how this magnetic instability, which is pronounced in a single monolayer, can enable sizable singlet-triplet mixing of the superconducting order parameter, contrary to contemporary considerations of the pairing symmetry in monolayer NbSe₂, and discuss approaches as to how this degree of mixing can be addressed quantitatively within our DFT framework. Our calculations also enable a quantitative description of the large anisotropy of the superconducting critical field, using DFT calculations of monolayer NbSe₂ in the normal state.
