Nontrivial Boundary-Mediated Superconducting Transport in a TRSB Topological Iron-Based Superconductor

@misc{liu2026nontrivial,
  title = {{Nontrivial Boundary-Mediated Superconducting Transport in a TRSB Topological Iron-Based Superconductor}},
  author = {Wenyao Liu and Gabriel Natale and Camron Farhang and Michael Geiwitz and Qishuo Tan and Xingyao Guo and Mason Gray and Vincent LambertiJazzmin Victorin and Huairuo Zhang and James L. Hart and Vsevolod Belosevich and Xi Ling and Qiong Ma and Wan Kyu Park and Kenji Watanabe and Takashi Taniguchi and Judy J. Cha and Albert V. Davydov and Kin Chung Fong and Ethan Arnault and Genda Gu and Rui-Xing Zhang and Enrico Rossi and Jing Xia and Kenneth S. Burch},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2606.21507},
  eprint = {2606.21507},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2606.21507},
}

TY  - UNPB
TI  - Nontrivial Boundary-Mediated Superconducting Transport in a TRSB Topological Iron-Based Superconductor
AU  - Wenyao Liu
AU  - Gabriel Natale
AU  - Camron Farhang
AU  - Michael Geiwitz
AU  - Qishuo Tan
AU  - Xingyao Guo
AU  - Mason Gray
AU  - Vincent LambertiJazzmin Victorin
AU  - Huairuo Zhang
AU  - James L. Hart
AU  - Vsevolod Belosevich
AU  - Xi Ling
AU  - Qiong Ma
AU  - Wan Kyu Park
AU  - Kenji Watanabe
AU  - Takashi Taniguchi
AU  - Judy J. Cha
AU  - Albert V. Davydov
AU  - Kin Chung Fong
AU  - Ethan Arnault
AU  - Genda Gu
AU  - Rui-Xing Zhang
AU  - Enrico Rossi
AU  - Jing Xia
AU  - Kenneth S. Burch
PY  - 2026
DA  - 2026/10/22
PB  - arXiv
DO  - 10.48550/arxiv.2606.21507
UR  - https://arxiv.org/abs/2606.21507
AB  - The interplay of superconductivity, band topology, and spontaneous time-reversal-symmetry breaking (TRSB) is expected to enable topological superconducting boundary states. FeTe0.55Se0.45 provides a promising single-material platform because it combines superconductivity, nontrivial band topology, and spontaneous magnetization in the superconducting state. Here we report evidence for a boundary-mediated superconducting transport response in exfoliated Fe(Te,Se) devices. Polar Kerr measurements show that TRSB emerges below TKerr < Tc and coexists with superconductivity across multiple compositions, providing an independent symmetry-breaking scale for transport. Using crystallographically sharp, continuous edges and side-surface-dominant contacts, we find that topological FeTe0.55Se0.45 exhibits an anomalous conductance plateau absent in topologically trivial FeTe0.40Se0.60 and Fe1.02Te0.55Se0.45 under comparable measurements. This plateau requires uninterrupted sharp edges connecting source and drain, persists over micrometer-scale separations far exceeding the bulk coherence length, shows strongly suppressed thermal broadening, and collapses when the drain is moved to the top surface. Its temperature evolution follows the TRSB scale: the plateau remains weakly broadened below T*Kerr and disappears near TKerr rather than Tc. These doping-selective, edge-geometry-dependent, TRSB-correlated, and long-range nonlocal signatures establish experimental criteria for identifying boundary-mediated superconducting transport in FeTe0.55Se0.45 and motivate phase-sensitive and theoretical studies of its microscopic origin.
ER  -