Resolving unconventional gap structure in kagome superconductors with hybrid microwave circuits

@misc{lee2026resolving,
  title = {{Resolving unconventional gap structure in kagome superconductors with hybrid microwave circuits}},
  author = {Yejin Lee and Haolin Jin and Sushmita Chandra and Berit H. Goodge and Edouard Lesne and Tommaso Confalone and Francesco Tafuri and Davide Massarotti and Golam Haider and Kornelius Nielsch and Bernd Büchner and Claudia Felser and Debanjan Chowdhury and Nicola Poccia and Uri Vool},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.00964},
  eprint = {2609.00964},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.00964},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Resolving unconventional gap structure in kagome superconductors with hybrid microwave circuits
AU  - Yejin Lee
AU  - Haolin Jin
AU  - Sushmita Chandra
AU  - Berit H. Goodge
AU  - Edouard Lesne
AU  - Tommaso Confalone
AU  - Francesco Tafuri
AU  - Davide Massarotti
AU  - Golam Haider
AU  - Kornelius Nielsch
AU  - Bernd Büchner
AU  - Claudia Felser
AU  - Debanjan Chowdhury
AU  - Nicola Poccia
AU  - Uri Vool
PY  - 2026
DA  - 2026/09/01
PB  - arXiv
DO  - 10.48550/arxiv.2609.00964
UR  - https://arxiv.org/abs/2609.00964
AB  - Unconventional superconductivity is a hallmark of exotic quantum matter, where determining the pairing symmetry is essential for uncovering its microscopic origin. Kagome superconductors provide a fertile landscape for emergent phenomena arising from strong electronic correlations and nontrivial band topology, yet their superconducting pairing symmetry remains elusive. The superconducting gap structure is commonly probed via electrodynamic response, but such measurements are inapplicable to thin flakes due to their small volume and delicate nature. Superconducting microwave resonators offer a coherent and highly sensitive platform for probing electrodynamic responses, with versatile designs that enable incorporation of diverse materials and geometries. Here, we integrate flakes into microwave circuits, enabling noninvasive access to the superfluid response through contactless coupling that preserves structural integrity. By engineering the device geometry to suppress parasitic two-level-system losses that dominate dissipation in microwave circuits, we isolate the intrinsic material response. Remarkably, the temperature-dependent superfluid density exhibits linear behavior at low temperatures, consistent with a nodal gap structure. Our approach establishes a noninvasive platform for probing electrodynamic response of fragile superconducting flakes while advancing hybrid microwave architectures for quantum technologies.
ER  -