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arXiv · 1605.00120

Tuning of magnetic quantum criticality in artificial Kondo superlattice CeRhIn5/YbRhIn5

T. Ishii·R. Toda·Y. Hanaoka·Y. Tokiwa·M. Shimozawa·Y. Kasahara·R. Endo·T. Terashima·A. H. Nevidomskyy·T. Shibauchi·Y. Matsuda
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Abstract

The effects of reduced dimensions and the interfaces on antiferromagnetic quantum criticality are studied in epitaxial Kondo superlattices, with alternating $n$ layers of heavy-fermion antiferromagnet CeRhIn$_5$ and 7 layers of normal metal YbRhIn$_5$. As $n$ is reduced, the Kondo coherence temperature is suppressed due to the reduction of effective Kondo screening. The Néel temperature is gradually suppressed as $n$ decreases and the quasiparticle mass is strongly enhanced, implying dimensional control toward quantum criticality. Magnetotransport measurements reveal that a quantum critical point is reached for $n=3$ superlattice by applying small magnetic fields. Remarkably, the anisotropy of the quantum critical field is opposite to the expectations from the magnetic susceptibility in bulk CeRhIn$_5$, suggesting that the Rashba spin-orbit interaction arising from the inversion symmetry breaking at the interface plays a key role for tuning the quantum criticality in the two-dimensional Kondo lattice.

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T. Ishii, R. Toda, Y. Hanaoka, Y. Tokiwa, M. Shimozawa, Y. Kasahara, R. Endo, T. Terashima, A. H. Nevidomskyy, T. Shibauchi, Y. Matsuda. 2016-04-30. Tuning of magnetic quantum criticality in artificial Kondo superlattice CeRhIn5/YbRhIn5. https://doi.org/10.1103/physrevlett.116.206401

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