We have studied the superlattices with alternating block layers (BLs) of heavy-fermion superconductor CeCoIn5 and conventional-metal YbCoIn5 by site-selective nuclear magnetic resonance(NMR) spectroscopy, which uniquely offers spatially-resolved dynamical magnetic information. We find that the presence of antiferromagnetic fluctuations is confined to the Ce-BLs, indicating that magnetic degrees of freedom of f-electrons are quenched inside the Yb-BLs. Contrary to simple expectations that the two-dimensionalization enhances fluctuations, we observe that antiferromagnetic fluctuations are rapidly suppressed with decreasing Ce-BL thickness. Moreover, the suppression is more prominent near the interfaces between the BLs. These results imply significant effects of local inversion-symmetry breaking at the interfaces.
@article{arxiv.1511.04209,
title = {The interface between heavy fermions and normal electrons investigated by spatially-resolved nuclear magnetic resonance},
author = {Takayoshi Yamanaka and Masaaki Shimozawa and Ryota Endo and Yuta Mizukam and Hiroaki Shishido and Takahito Terashima and Takasada Shibauchi and Yuji Matsuda and Kenji Ishida},
journal= {arXiv preprint arXiv:1511.04209},
year = {2016}
}
Comments
5 pages, 4 figures, accepted for publication as a Rapid Communication in Physical Review B