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arXiv · 2406.09607

Gate voltage modulation of the superconducting state in a degenerate semiconductor

Bikash C. Barik·Himadri Chakraborti·Buddhadeb Pal·Aditya K. Jain·Swagata Bhunia·Sounak Samanta·Apurba Laha·Suddhasatta Mahapatra·K. Das Gupta
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Abstract

In this work, we demonstrate that the modulation of carrier density can alter the superconducting transition temperature by up to $204$ mK in epitaxial Indium Nitride on Gallium Nitride, accounting for the $10$% of the transition temperature in ungated conditions. Our samples are likely free from strong localization effects and significant granularity, as indicated by $( k_{f l} \gg 1 )$, suggesting that the primary determinant of the transition temperature in InN is carrier density, rather than disorder scattering. The observed behavior is consistent with BCS s-wave superconductivity, corroborated by the superconducting parameters we measured. Furthermore, we observed a $60$% bipolar suppression of the supercurrent in our experiments.

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Bikash C. Barik, Himadri Chakraborti, Buddhadeb Pal, Aditya K. Jain, Swagata Bhunia, Sounak Samanta, Apurba Laha, Suddhasatta Mahapatra, K. Das Gupta. 2024-06-13. Gate voltage modulation of the superconducting state in a degenerate semiconductor. https://arxiv.org/abs/2406.09607

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