A d-Electron Heavy-Fermion-Like Superconductor with Frustration-Induced Flat Bands

Chaoguo Wang; Hyeonhu Bae; Jiaqi Tian; Qing-Ping Ding; Yongbin Lee; Yuji Furukawa; Shannon Gould; Brianna R. Billingsley; Si Athena Chen; Matthias Frontzek; Tai Kong; Binghai Yan; Sheng Ran; Xin Gui

arXiv · 2607.09924

A d-Electron Heavy-Fermion-Like Superconductor with Frustration-Induced Flat Bands

Chaoguo Wang·Hyeonhu Bae·Jiaqi Tian·Qing-Ping Ding·Yongbin Lee·Yuji Furukawa·Shannon Gould·Brianna R. Billingsley·Si Athena Chen·Matthias Frontzek·Tai Kong·Binghai Yan·Sheng Ran·Xin Gui

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Abstract

Heavy-fermion superconductors are mostly associated with f-electron materials with Kondo lattices, while known d-electron heavy-fermion-like systems are often linked to orbital-selective local moments, Hund-metal physics, or a charge-density-wave mechanism. Here we report Mo4PtGa17, a noncentrosymmetric itinerant d-electron superconductor with a geometrically frustrated breathing-pyrochlore Mo lattice. Thermodynamic, transport and NMR measurements reveal heavy-fermion-like behavior superconductivity and dominant ferromagnetic spin fluctuations near a ferromagnetic instability. Theoretical calculations identify nearly flat bands, van Hove singularities and Kramers nodal lines near the Fermi energy, derived intrinsically from Mo-4d states and are robust against on-site electronic correlations. These results suggest that the geometrically frustrated lattice in Mo4PtGa17 generates an intriguing electronic structure that enhances the density of states, spin susceptibility and quasiparticle mass. Mo4PtGa17 therefore identifies a unique route to heavy-fermion-like superconductivity in d-electron materials through geometrical frustration, different from the previously reported systems.

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Chaoguo Wang, Hyeonhu Bae, Jiaqi Tian, Qing-Ping Ding, Yongbin Lee, Yuji Furukawa, Shannon Gould, Brianna R. Billingsley, Si Athena Chen, Matthias Frontzek, Tai Kong, Binghai Yan, Sheng Ran, Xin Gui. 2026-07-10. A d-Electron Heavy-Fermion-Like Superconductor with Frustration-Induced Flat Bands. https://arxiv.org/abs/2607.09924

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