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.Comment: 5 pages, 4 figure

Fisk, Z.

Jang, Tae-Hwan

Kim, D. J.

Rößler, S.

Steglich, F.

Tjeng, L. H.

Wirth, S.

English

arXiv

Hybridization between conduction electrons and the strongly interacting f-electrons in rare earth or actinide compounds may result in new states of matter. Depending on the exact location of the concomitant hybridization gap with respect to the Fermi energy, a heavy fermion or an insulating ground state ensues. To study this entanglement locally, we conducted scanning tunneling microscopy and spectroscopy (STS) measurements on the "Kondo insulator" SmB6. The vast majority of surface areas investigated were reconstructed, but infrequently, patches of varying sizes of nonreconstructed Sm- or B-terminated surfaces also were found. On the smallest patches, clear indications for the hybridization gap with logarithmic temperature dependence (as expected for a Kondo system) and for intermultiplet transitions were observed. On nonreconstructed surface areas large enough for coherent cotunneling, we were able to observe clear-cut Fano resonances. Our locally resolved STS indicated considerable finite conductance on all surfaces independent of their structure, not proving but leaving open the possibility of the existence of a topologically protected surface state

Rößler, Sahana

Kim, Dae-Jeong

Tjeng, LH

Fisk, Zachary

Steglich, Frank

Wirth, Steffen

eScholarship - University of California

Hybridization gap and Fano resonance in SmB6

Significance
          
            Quantum entanglement may give rise to emerging phenomena and new states of matter. In the intermediate-valence material SmB
            6
            , this is realized via hybridization between localized 4
            f
            and conduction band states that, at sufficiently low temperatures, results in the screening of the 4
            f
            local moments by the conduction electrons and produces a so-called Kondo resonance in the density of states. The latter is examined by scanning tunneling spectroscopy down to temperatures well below the Kondo temperature. This atomically resolved spectroscopy allows one to distinguish between reconstructed and pristine surfaces and different surface terminations, all of which influence the spectroscopic results. These insights are vital for other, less local spectroscopic tools in the context of possible topologically protected surface states.
          </jats:p

Sahana Rößler

Tae-Hwan Jang

Dae-Jeong Kim

L. H. Tjeng

Zachary Fisk

Frank Steglich

Steffen Wirth

Crossref

Proceedings of the National Academy of Sciences

Hybridization gap and Fano resonance in SmB
            <sub>6</sub>

Hybridization between conduction electrons and the strongly interacting f-electrons in rare earth or actinide compounds may result in new states of matter. Depending on the exact location of the concomitant hybridization gap with respect to the Fermi energy, a heavy fermion or an insulating ground state ensues. To study this entanglement locally, we conducted scanning tunneling microscopy and spectroscopy (STS) measurements on the “Kondo insulator” SmB6. The vast majority of surface areas investigated were reconstructed, but infrequently, patches of varying sizes of nonreconstructed Sm- or B-terminated surfaces also were found. On the smallest patches, clear indications for the hybridization gap with logarithmic temperature dependence (as expected for a Kondo system) and for intermultiplet transitions were observed. On nonreconstructed surface areas large enough for coherent cotunneling, we were able to observe clear-cut Fano resonances. Our locally resolved STS indicated considerable finite conductance on all surfaces independent of their structure, not proving but leaving open the possibility of the existence of a topologically protected surface state

Jang, T.

Kim, D.

Tjeng, L.

MPG.PuRe

Hybridization gap and Fano resonance in SmB<sub>6</sub>

http://dx.doi.org/10.1073/pnas.1402643111

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

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

Abstract

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eScholarship - University of California

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MPG.PuRe

Hybridization gap and Fano resonance in SmB6{_6}6​

Abstract

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Available Versions

eScholarship - University of California

Crossref

MPG.PuRe

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