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arXiv · 1803.06097

Evolution of superconductivity in ultrathin NbS2

Rusen Yan·Guru Khalsa·Brian T. Schaefer·Alexander Jarjour·Sergei Rouvimov·Katja C. Nowack·Huili G. Xing·Debdeep Jena
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Abstract

We report a systematic study of thickness-dependent superconductivity and carrier transport properties in exfoliated layered 2H-NbS2. Hall-effect measurements reveal 2H-NbS2 in its normal state to be a p-type metal with hole mobility of 1-3 cm2/Vs. The superconducting transition temperature is found to decrease with thickness. We find that the suppression of superconductivity is due to disorder resulting from the incorporation of atmospheric oxygen and a reduced hole density. Cross-section transmission electron microscope (TEM) imaging reveals a chemical change of NbS2 in ambient conditions, resulting in the formation of amorphous oxide layers sandwiching crystalline layered NbS2. Though few-nm-thick 2H-NbS2 completely converts to amorphous oxide in ambient conditions, PMMA encapsulation prevents further chemical change and preserves superconductivity.

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Rusen Yan, Guru Khalsa, Brian T. Schaefer, Alexander Jarjour, Sergei Rouvimov, Katja C. Nowack, Huili G. Xing, Debdeep Jena. 2018-03-16. Evolution of superconductivity in ultrathin NbS2. https://doi.org/10.7567/1882-0786%2Faaff89

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