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Quantitative assessment of the role of spin fluctuations in the 2D Ising superconductor NbSe<sub>2</sub>

ORAL

Abstract

The recent discovery of a strong spin-orbit effect in superconducting NbSe2 monolayers, dubbed Ising superconductivity, has attracted a lot of attention. It was recently found that this material is close to magnetism. Thus it was proposed that spin fluctuations may play an important role in determining the superconducting order parameter (OP), in particular its parity. In our previous paper, we predicted spin fluctuations to be ferromagnetic, however, these calculations were utilizing uncontrollable approximations. In this talk, we report more accurate DFT calculations of the spin fluctuation spectrum, by calculating energies of spin spirals stabilized by artificially enhanced Hubbard interaction. From these calculation, the fully renormalized q-dependent DFT spin susceptibility can be extracted by inverting the RPA formula. It appears that the structure of spin fluctuations in the momentum space is more complicated than previously thought of. In the second part, we report state-of-the-art DFT calculations of the momentum-resolved electron-phonon coupling function α2F(k, k', ω). Together, the two parts provide a complete framework for addressing quantitatively the structure of the Ising OP in NbSe2.

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Presenters

  • Suvadip Das

    Department of Physics and Astronomy and Quantum Science and Engineering Center, George Mason University – Fairfax, VA, USA

Authors

  • Suvadip Das

    Department of Physics and Astronomy and Quantum Science and Engineering Center, George Mason University – Fairfax, VA, USA

  • Igor Mazin

    Physics & Astronomy, George Mason University, Department of Physics and Astronomy, George Mason University, George Mason University, Physics and Astronomy, George Mason University, Physics, George Mason University, Department of Physics and Astronomy,, George Mason University, Department of Physics and Astronomy and Quantum Science and Engineering Center, George Mason University – Fairfax, VA, USA

  • Elena R Margine

    Department of Physics, Applied Physics and Astronomy, Binghamton University-SUNY, Department of Physics, Applied Physics, and Astronomy, Binghamton University-SUNY, Department of Physics, Applied Physics and Astronomy, Binghamton University-SUNY – Binghamton, NY13902, USA, Department of Physics, Binghamton University-SUNY