Tuning the Magnetic Quantum Criticality of Artificial Kondo Superlattices CeRhIn_{5}/YbRhIn_{5}.
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 seven 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 a quantum critical point. Magnetotransport measurements reveal that a quantum critical point is reached for the 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.
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
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Ishii
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
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Toda
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
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Hanaoka
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.|Research Center for Low Temperature and Materials Science, Kyoto University, Kyoto 606-8501, Japan.
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Tokiwa
Institute for Solid State Physics, University of Tokyo, Kashiwa 277-8581, Japan.
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Shimozawa
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
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Kasahara
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
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Endo
Research Center for Low Temperature and Materials Science, Kyoto University, Kyoto 606-8501, Japan.
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Terashima
Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
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Nevidomskyy
Department of Advanced Materials Science, University of Tokyo, Chiba 277-8561, Japan.
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Shibauchi
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
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Matsuda