From orbital to paramagnetic pair breaking in layered superconductor 2H-NbS$_2$

Davide Pizzirani; Thom Ottenbros; Maró van Rijssel; Oleksandr Zheliuk; Yulia Kreminska; Malte Rösner; Jasper Linnartz; Anne de Visser; Nigel Hussey; Jianting Ye; Steffen Wiedmann; Maarten van Delft

doi:10.1103/physrevresearch.6.l042006

arXiv · 2404.03461

From orbital to paramagnetic pair breaking in layered superconductor 2H-NbS$_2$

Davide Pizzirani·Thom Ottenbros·Maró van Rijssel·Oleksandr Zheliuk·Yulia Kreminska·Malte Rösner·Jasper Linnartz·Anne de Visser·Nigel Hussey·Jianting Ye·Steffen Wiedmann·Maarten van Delft

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Abstract

The superconducting transition metal dichalcogenides 2H-NbSe$_2$ and 2H-NbS$_2$ are intensively studied on account of their unique electronic properties such as Ising superconductivity, found in multi- and monolayers, with upper critical fields beyond the Pauli limit. Even in bulk crystals, there are reports of multiband superconductivity and exotic states, such as the Fulde-Ferrell-Larkin-Ovchinnikov phase. In this work, we investigate the superconducting properties of 2H-NbS$_2$ through a detailed high-field mapping of the phase diagram by means of magnetotransport and magnetostriction experiments. We compare the phase diagram between bulk crystals and a 6~nm thick flake of 2H-NbS$_2$ and find a drastically enhanced Maki parameter in the flake, signifying a change of the relevant pair breaking mechanism from orbital to paramagnetic pair breaking, which we attribute to an effect of enhanced spin-orbit coupling.

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Davide Pizzirani, Thom Ottenbros, Maró van Rijssel, Oleksandr Zheliuk, Yulia Kreminska, Malte Rösner, Jasper Linnartz, Anne de Visser, Nigel Hussey, Jianting Ye, Steffen Wiedmann, Maarten van Delft. 2024-04-04. From orbital to paramagnetic pair breaking in layered superconductor 2H-NbS$_2$. https://doi.org/10.1103/physrevresearch.6.l042006

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