Exceptional Superconducting Interfaces between Graphene and Atomic Chains in A15-MoRe
Abstract
Realizing highly transparent and magnetic-field-resilient superconducting contacts is a critical bottleneck for the advancement of two-dimensional (2D) quantum devices. Molybdenum-rhenium (MoRe) alloys have been empirically favored as they uniquely yield ballistic, highly transparent contacts to graphene that survive in high-magnetic-field regimes; however, the microscopic origin of this anomalous transparency has remained a long-standing puzzle. Here, we resolve this paradox by revealing that pristine graphene/MoRe interfaces are governed by the classical A15 superconducting phase. Combining low-temperature transport, X-ray diffraction, and atomic-resolution electron microscopy, we demonstrate that as-deposited MoRe spontaneously forms the A15 phase in direct contact with graphene, whereas thermal annealing triggers a phase transition to a hexagonal close-packed (hcp) structure that severely degrades the Josephson transparency. Crucially, the one-dimensional (1D) transition-metal atomic chains unique to the A15 structure exhibit a near-perfect lattice match (mismatch < 1%) with graphene edges. First-principles calculations further prove that the d-orbitals of these historically renowned 1D chains possibly hybridize with graphene's Dirac cone near the K point. These findings not only uncover the structural and electronic origins of optimal MoRe contacts but also establish A15-phase superconductors as a geometrically ideal, universal platform for realizing robust quantum electronics based on 2D materials.
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BibTeX
@misc{ogura2026exceptional,
title = {{Exceptional Superconducting Interfaces between Graphene and Atomic Chains in A15-MoRe}},
author = {Hiroto Ogura and Yuto Tsukidate and Shun Kondo and Zhuoqun Li and Natsuki Sasaki and Tsunenobu Sato and Azusa Utsumi and Tomohiro Otsuka and Mitsuhiro Saito and Kazutoshi Inoue and Takashi Taniguchi and Kenji Watanabe and Yuichi Ikuhara and Toshiaki Kato},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.39694},
eprint = {2610.39694},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.39694},
}
RIS
TY - UNPB
TI - Exceptional Superconducting Interfaces between Graphene and Atomic Chains in A15-MoRe
AU - Hiroto Ogura
AU - Yuto Tsukidate
AU - Shun Kondo
AU - Zhuoqun Li
AU - Natsuki Sasaki
AU - Tsunenobu Sato
AU - Azusa Utsumi
AU - Tomohiro Otsuka
AU - Mitsuhiro Saito
AU - Kazutoshi Inoue
AU - Takashi Taniguchi
AU - Kenji Watanabe
AU - Yuichi Ikuhara
AU - Toshiaki Kato
PY - 2026
DA - 2026/10/29
PB - arXiv
DO - 10.48550/arxiv.2610.39694
UR - https://arxiv.org/abs/2610.39694
AB - Realizing highly transparent and magnetic-field-resilient superconducting contacts is a critical bottleneck for the advancement of two-dimensional (2D) quantum devices. Molybdenum-rhenium (MoRe) alloys have been empirically favored as they uniquely yield ballistic, highly transparent contacts to graphene that survive in high-magnetic-field regimes; however, the microscopic origin of this anomalous transparency has remained a long-standing puzzle. Here, we resolve this paradox by revealing that pristine graphene/MoRe interfaces are governed by the classical A15 superconducting phase. Combining low-temperature transport, X-ray diffraction, and atomic-resolution electron microscopy, we demonstrate that as-deposited MoRe spontaneously forms the A15 phase in direct contact with graphene, whereas thermal annealing triggers a phase transition to a hexagonal close-packed (hcp) structure that severely degrades the Josephson transparency. Crucially, the one-dimensional (1D) transition-metal atomic chains unique to the A15 structure exhibit a near-perfect lattice match (mismatch < 1%) with graphene edges. First-principles calculations further prove that the d-orbitals of these historically renowned 1D chains possibly hybridize with graphene's Dirac cone near the K point. These findings not only uncover the structural and electronic origins of optimal MoRe contacts but also establish A15-phase superconductors as a geometrically ideal, universal platform for realizing robust quantum electronics based on 2D materials.
ER -