Coupling between heavy fermion superconductor CeCoIn$_5$ and antiferromagnetic metal CeIn$_3$ through the atomic interface

M. Naritsuka; S. Nakamura; Y. Kasahara; T. Terashima; R. Peters; Y. Matsuda

doi:10.1103/PhysRevB.100.024507

paper

Coupling between heavy fermion superconductor CeCoIn $_{5}$ and antiferromagnetic metal CeIn $_{3}$ through the atomic interface

arXiv:1904.06937 · doi:10.1103/PhysRevB.100.024507

Abstract

To study the mutual interaction between unconventional superconductivity and magnetic order through an interface, we fabricate Kondo superlattices consisting of alternating layers of heavy-fermion superconductor CeCoIn $_{5}$ and antiferromagnetic (AFM) heavy-fermion metal CeIn $_{3}$ . The strength of the AFM fluctuations is tuned by applying hydrostatic pressure to CeCoIn $_{5} (m)$ /CeIn $_{3} (n)$ superlattices with $m$ and $n$ unit-cell-thick layers of CeCoIn $_{5}$ and CeIn $_{3}$ , respectively. Superconductivity in CeCoIn $_{5}$ and AFM order in CeIn $_{3}$ coexist in spatially separated layers. At ambient pressure, Néel temperature $T_{N}$ of the CeIn $_{3}$ block layers (BLs) of CeCoIn $_{5}$ (7)/CeIn $_{3} (n)$ shows little dependence on $n$ , in contrast to CeIn $_{3} (n)$ /LaIn $_{3}$ (4) superlattices where $T_{N}$ is strongly suppressed with decreasing $n$ . This suggests that each CeIn $_{3}$ BL is magnetically coupled by the RKKY interaction through the adjacent CeCoIn $_{5}$ BL and a 3D magnetic state is formed. With applying pressure to CeCoIn $_{5}$ (7)/CeIn $_{3}$ (13), $T_{N}$ of the CeIn $_{3}$ BLs is suppressed up to 2.4 GPa, showing a similar pressure dependence as CeIn $_{3}$ single crystals. An analysis of upper critical field reveals that the superconductivity in the CeCoIn $_{5}$ BLs is barely influenced by the AFM fluctuations in the CeIn $_{3}$ BLs, even when the CeIn $_{3}$ BLs are in the vicinity of the AFM quantum critical point. This is in stark contrast to CeCoIn $_{5}$ /CeRhIn $_{5}$ superlattice where the superconductivity in the CeCoIn $_{5}$ BLs is profoundly affected by AFM fluctuations in the CeRhIn $_{5}$ BLs. The present results show that although AFM fluctuations are injected into the CeCoIn $_{5}$ BLs from the CeIn $_{3}$ BLs through the interface, they barely affect the force which binds superconducting electron pairs. These results demonstrate that 2D AFM fluctuations are essentially important for the pairing interactions in CeCoIn $_{5}$ .

arXiv comment8 pages, 9 figures

Coupling between heavy fermion superconductor CeCoIn $_{5}$ and antiferromagnetic metal CeIn $_{3}$ through the atomic interface

Abstract

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Cited by in corpus (2)

Coupling between heavy fermion superconductor CeCoIn5​ and antiferromagnetic metal CeIn3​ through the atomic interface

Abstract

References in corpus (34)

Cited by in corpus (2)

Coupling between heavy fermion superconductor CeCoIn $_{5}$ and antiferromagnetic metal CeIn $_{3}$ through the atomic interface