Resolving unconventional gap structure in kagome superconductors with hybrid microwave circuits
Year: 2026
Type: preprint
Abstract: 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.
Source: arXiv (Cornell University)
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: Fortschritte bei den Methoden zur Realisierung thermoelektrischer Schaltungen in verdrillten VanderWaalsHochtemperaturKupferheterostrukturen, AxionElektrodynamik von SupraleiterTopologischeIsolatorHeterostrukturen, G4556751752, G5443090575, G5473878947, Kontrolle starker Korrelationen von HochtemperaturSupraleitern mit VanderWaalsHeterostrukturen
OpenAlex ID: W7206156582