重い電子系人工超格子CeCoIn[5]/YbCoIn[5] における NMR による研究

Abstract

A superlattice is a multilayered structure of two or more materials and its characteristic structure is expected to show fascinating phenomena originating from the two dimensionalization, its interfaces, proximity effects, and so on. In the studies of the superlattices, microscopic information of each block layers (BLs) and its interfaces will lead us to understand the superlattice physics more in details, but such measurements have not been reported so far. To investigate the electronic and magnetic properties of each BL in the superlattices, we have performed a nuclear magnetic resonance measurement, which is one of the most suitable microscopic probes, on the CeCoIn[5]/YbCoIn[5] superlattices. We clarified that in the CeCoIn5 BLs (Ce BLs), antiferromagnetic (AFM) spin fluctuations are suppressed whereas the YbCoIn5 BLs show a conventional-metal behavior. Furthermore, we distinguished the signals of Ce BLs arising from the inner and interfacial layers, and found that AFM fluctuations are suppressed at the interfacial layers.