Nodeless d-wave pairing in monolayer FeSe revealed by intra-unit-cell Josephson interferometry
Abstract
The Josephson effect provides a direct phase-sensitive probe of superconducting order and has played a central role in identifying unconventional pairing symmetries1-6. Conventional Josephson interferometry, however, extracts phase information through engineered junction geometries and crystallographic orientations, rather than by resolving the internal phase structure of the pair state within a single unit cell. Here, we use a superconducting Nb tip to realize atomic-scale Josephson interferometry in monolayer FeSe/SrTiO3. Despite a fully gapped quasiparticle spectrum, the local Josephson response exhibits a striking intra-unit-cell pattern, with maxima centred on Fe-Fe bonds and robust nodal lines along the Fe-Se directions. We show that these nodal lines arise from destructive interference between Josephson tunnelling amplitudes associated with opposite-sign pairing components. Microscopic calculations reproduce the observed spatial pattern and identify it as a fingerprint of nodeless d-wave pairing. Our results establish intra-unit-cell Josephson interferometry as a local phase-sensitive probe of pairing symmetry in unconventional superconductors.
Related
- Nodeless d-wave superconductivity driven by charge fluctuations in monolayer FeSe on SrTiO3
- Josephson interferometry in an Oppenheimer--Snyder-like scale-dependent black-hole spacetime
- Microscopic Origin and Josephson Signatures of d-Wave Superconductivity in Monolayer FeSe
- Structural control of two-level defect density revealed by high-throughput correlative measurements of Josephson junctions
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BibTeX
@misc{li2026nodeless,
title = {{Nodeless d-wave pairing in monolayer FeSe revealed by intra-unit-cell Josephson interferometry}},
author = {Runxin Li and Yuchen Huo and Jiong Mei and Ming-Qiang Ren and Miaomiao Wang and Quanxing Wei and Fengyu Yao and Maowen Zheng and Qing Qu and Cui Ding and Hongtao Yuan and Zhuoyu Chen and Wei-Qiang Chen and Kun Jiang and Qi-Kun Xue and Yu-Jie Sun},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.34382},
eprint = {2610.34382},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.34382},
}
RIS
TY - UNPB
TI - Nodeless d-wave pairing in monolayer FeSe revealed by intra-unit-cell Josephson interferometry
AU - Runxin Li
AU - Yuchen Huo
AU - Jiong Mei
AU - Ming-Qiang Ren
AU - Miaomiao Wang
AU - Quanxing Wei
AU - Fengyu Yao
AU - Maowen Zheng
AU - Qing Qu
AU - Cui Ding
AU - Hongtao Yuan
AU - Zhuoyu Chen
AU - Wei-Qiang Chen
AU - Kun Jiang
AU - Qi-Kun Xue
AU - Yu-Jie Sun
PY - 2026
DA - 2026/10/25
PB - arXiv
DO - 10.48550/arxiv.2610.34382
UR - https://arxiv.org/abs/2610.34382
AB - The Josephson effect provides a direct phase-sensitive probe of superconducting order and has played a central role in identifying unconventional pairing symmetries1-6. Conventional Josephson interferometry, however, extracts phase information through engineered junction geometries and crystallographic orientations, rather than by resolving the internal phase structure of the pair state within a single unit cell. Here, we use a superconducting Nb tip to realize atomic-scale Josephson interferometry in monolayer FeSe/SrTiO3. Despite a fully gapped quasiparticle spectrum, the local Josephson response exhibits a striking intra-unit-cell pattern, with maxima centred on Fe-Fe bonds and robust nodal lines along the Fe-Se directions. We show that these nodal lines arise from destructive interference between Josephson tunnelling amplitudes associated with opposite-sign pairing components. Microscopic calculations reproduce the observed spatial pattern and identify it as a fingerprint of nodeless d-wave pairing. Our results establish intra-unit-cell Josephson interferometry as a local phase-sensitive probe of pairing symmetry in unconventional superconductors.
ER -