Fully Gapped Superconductivity in the Nonsymmorphic Centrosymmetric Superconductor In2Bi
Abstract
The nature of superconductivity in nonsymmorphic In2Bi remains an open question, with ongoing debate over whether it exhibits conventional (BCS-like) or unconventional superconductivity. Here we report the physical characteristics and superconducting properties of polycrystalline In2Bi. Measurements of electrical resistivity, magnetization, penetration depth, and specific heat demonstrate the superconducting transition temperature about 6 K, with a sharp transition in resistivity (Delta_Tc = 0.1 K) and RRR = 57.32, reflecting the high quality of the sample. The upper critical field Hc2(0) obtained from resistivity and magnetization measurements are in good agreement with each other and are smaller than the Pauli limit, suggesting orbital limited mechanism. The coherence length = 35.43 nm, penetration depth = 101.9 nm and electron-phonon coupling constant = 1.05 suggest strongly coupled type-II superconductivity. For T<Tc, Delta_lambda(T) is best described by an s-wave BCS model and does not have any power law dependency with T, which is expected for a nodeless superconducting order parameter. The superfluid density reveals a fully gapped superconductivity with a gap of 2Delta_0/kBTc = 4.02. In the superconducting state, the electronic specific heat is best described by an s-wave BCS model with a gap of 2Delta_0/kBTc = 4.05. All these results from the present study indicate that In2Bi is a typical type-II,BCS-like, strongly coupled, and fully gapped superconductor in the dirty limit.
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BibTeX
@misc{gangwar2026fully,
title = {{Fully Gapped Superconductivity in the Nonsymmorphic Centrosymmetric Superconductor In2Bi}},
author = {Atul Gangwar and Kunal Yadav and Barnabha bandyopadhyay and S. Patnaik and K. G. Suresh and Sandip Chatterjee},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.22917},
eprint = {2610.22917},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.22917},
}
RIS
TY - UNPB
TI - Fully Gapped Superconductivity in the Nonsymmorphic Centrosymmetric Superconductor In2Bi
AU - Atul Gangwar
AU - Kunal Yadav
AU - Barnabha bandyopadhyay
AU - S. Patnaik
AU - K. G. Suresh
AU - Sandip Chatterjee
PY - 2026
DA - 2026/10/16
PB - arXiv
DO - 10.48550/arxiv.2610.22917
UR - https://arxiv.org/abs/2610.22917
AB - The nature of superconductivity in nonsymmorphic In2Bi remains an open question, with ongoing debate over whether it exhibits conventional (BCS-like) or unconventional superconductivity. Here we report the physical characteristics and superconducting properties of polycrystalline In2Bi. Measurements of electrical resistivity, magnetization, penetration depth, and specific heat demonstrate the superconducting transition temperature about 6 K, with a sharp transition in resistivity (Delta_Tc = 0.1 K) and RRR = 57.32, reflecting the high quality of the sample. The upper critical field Hc2(0) obtained from resistivity and magnetization measurements are in good agreement with each other and are smaller than the Pauli limit, suggesting orbital limited mechanism. The coherence length = 35.43 nm, penetration depth = 101.9 nm and electron-phonon coupling constant = 1.05 suggest strongly coupled type-II superconductivity. For T<Tc, Delta_lambda(T) is best described by an s-wave BCS model and does not have any power law dependency with T, which is expected for a nodeless superconducting order parameter. The superfluid density reveals a fully gapped superconductivity with a gap of 2Delta_0/kBTc = 4.02. In the superconducting state, the electronic specific heat is best described by an s-wave BCS model with a gap of 2Delta_0/kBTc = 4.05. All these results from the present study indicate that In2Bi is a typical type-II,BCS-like, strongly coupled, and fully gapped superconductor in the dirty limit.
ER -