Hybridization gap and Fano resonance in SmB${_6}$

Authors :: Rößler, S.
Jang, Tae-Hwan
Kim, D. J.
Tjeng, L. H.
Fisk, Z.
Steglich, F.
Wirth, S.
Source :: Proc. Natl. Acad. Sci. USA 111 (2014) 4798 (OPEN ACCESS)
Publication Year :: 2013
Abstract: We present results of Scanning Tunneling Microscopy and Spectroscopy (STS) measurements on the "Kondo insulator" SmB$_6$. The vast majority of surface areas investigated was reconstructed but, infrequently, also patches of varying size of non-reconstructed, Sm- or B-terminated surfaces were found. On the smallest patches, clear indications for the hybridization gap and inter-multiplet transitions were observed. On non-reconstructed surface areas large enough for coherent co-tunneling we were able to observe clear-cut Fano resonances. Our locally resolved STS indicated considerable finite conductance on all surfaces independent of their structure.<br />Comment: 5 pages, 4 figures