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arXiv · 2103.15197

Reentrant orbital effect against superconductivity in the quasi-two-dimensional superconductor NbS$_2$

Andrei G. Lebed
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Abstract

We derive integral equation for superconducting gap, which takes into account the quantum nature of electron motion in a parallel magnetic field in a quasi-two-dimensional (Q2D) superconductor in the presence of a non-zero perpendicular field component. By comparison of our theoretical results with the recent experimental data obtained on the NbS$_2$, we show that the orbital effect against superconductivity partially destroys superconductivity in the so-called Ginzburg-Landau area of this Q2D conductor, as expected. Nevertheless, at relatively high magnetic fields, $H \simeq 15 \ T$, the orbital effect starts to improve the Fulde-Ferrell-Larkin-Ovchinnikov phase in the NbS$_2$, due to the quantum nature of electron motion in a parallel magnetic field. In our opinion, this is the most clear demonstration that the orbital effect against superconductivity in a parallel magnetic field has a reversible nature.

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Andrei G. Lebed. 2021-03-28. Reentrant orbital effect against superconductivity in the quasi-two-dimensional superconductor NbS$_2$. https://doi.org/10.1134/s0021364021200017

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