Fully Suppressed Superconductivity in Nonferromagnetic Heavy Fermion/Superconductor Bilayers: Rocksalt-Type CeO/LaO.

Sekine, Mikito; Negishi, Masamichi; Sasaki, Satoshi; Yoshimura, Hidetatsu; Kimura, Noriaki; Fukumura, Tomoteru · ACS Nano · 2026

basic_science · Level V

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Abstract

Superconductor/ferromagnet heterostructures have been investigated extensively because of their capability to break superconducting electron pairs. In this study, we report on heterostructures of a superconductor and heavy-fermion system as an alternative platform for a strong pair-breaking proximity effect. We fabricated rocksalt-type CeO/LaO heteroepitaxial bilayers, where LaO is a superconductor and CeO is a nonferromagnetic heavy-fermion system. While LaO(9.5-21 nm) thin films showed superconductivity below 4.4-5.2 K, the CeO(4.8-5.8 nm)/LaO(9.2-17 nm) bilayers showed no trace of superconductivity down to 0.025 K. This result demonstrates a strong pair-breaking effect at the superconductor/heavy-fermion system heteroepitaxial interface. This effect would provide a useful platform for superconducting micro and nano devices.