scholarly journals Planar tunneling spectroscopy of the topological Kondo insulator SmB6

2017 ◽  
Vol 95 (19) ◽  
Author(s):  
L. Sun ◽  
D.-J. Kim ◽  
Z. Fisk ◽  
W. K. Park
Keyword(s):  
Tunneling Spectroscopy ◽  
Kondo Insulator ◽  
Planar Tunneling

scholarly journals Magnetic and defect probes of the SmB6 surface state

2018 ◽  
Vol 4 (11) ◽  
pp. eaau4886 ◽  
Author(s):  
Lin Jiao ◽  
Sahana Rößler ◽  
Deepa Kasinathan ◽  
Priscila F. S. Rosa ◽  
Chunyu Guo ◽  
...  
Keyword(s):  
Surface States ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Magnetic Impurities ◽  
Fundamental Physics ◽  
Length Scales ◽  
Kondo Insulator ◽  
Theoretical Predictions ◽  
The Impact

The impact of nonmagnetic and magnetic impurities on topological insulators is a central focus concerning their fundamental physics and possible spintronics and quantum computing applications. Combining scanning tunneling spectroscopy with transport measurements, we investigate, both locally and globally, the effect of nonmagnetic and magnetic substituents in SmB6, a predicted topological Kondo insulator. Around the so-introduced substitutents and in accord with theoretical predictions, the surface states are locally suppressed with different length scales depending on the substituent’s magnetic properties. For sufficiently high substituent concentrations, these states are globally destroyed. Similarly, using a magnetic tip in tunneling spectroscopy also resulted in largely suppressed surface states. Hence, a destruction of the surface states is always observed close to atoms with substantial magnetic moment. This points to the topological nature of the surface states in SmB6 and illustrates how magnetic impurities destroy the surface states from microscopic to macroscopic length scales.

scholarly journals Topological surface states interacting with bulk excitations in the Kondo insulator SmB6 revealed via planar tunneling spectroscopy

2016 ◽  
Vol 113 (24) ◽  
pp. 6599-6604 ◽  
Author(s):  
Wan Kyu Park ◽  
Lunan Sun ◽  
Alexander Noddings ◽  
Dae-Jeong Kim ◽  
Zachary Fisk ◽  
...  
Keyword(s):  
Surface States ◽  
Spectroscopic Properties ◽  
Recent Theory ◽  
Tunneling Conductance ◽  
Strong Electron ◽  
Kondo Insulator ◽  
Single Crystal Surfaces ◽  
Planar Tunneling ◽  
Topological States ◽  
Protected Surface

Samarium hexaboride (SmB6), a well-known Kondo insulator in which the insulating bulk arises from strong electron correlations, has recently attracted great attention owing to increasing evidence for its topological nature, thereby harboring protected surface states. However, corroborative spectroscopic evidence is still lacking, unlike in the weakly correlated counterparts, including Bi2Se3. Here, we report results from planar tunneling that unveil the detailed spectroscopic properties of SmB6. The tunneling conductance obtained on the (001) and (011) single crystal surfaces reveals linear density of states as expected for two and one Dirac cone(s), respectively. Quite remarkably, it is found that these topological states are not protected completely within the bulk hybridization gap. A phenomenological model of the tunneling process invoking interaction of the surface states with bulk excitations (spin excitons), as predicted by a recent theory, provides a consistent explanation for all of the observed features. Our spectroscopic study supports and explains the proposed picture of the incompletely protected surface states in this topological Kondo insulator SmB6.

scholarly journals Probing the electronic structure of graphene near and far from the Fermi level via planar tunneling spectroscopy

2019 ◽  
Vol 115 (16) ◽  
pp. 163504
Author(s):  
John L. Davenport ◽  
Zhehao Ge ◽  
Junyan Liu ◽  
Carlos Nuñez-Lobato ◽  
Seongphill Moon ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Fermi Level ◽  
Tunneling Spectroscopy ◽  
Planar Tunneling

Tunneling spectroscopy in the Charge-Density Wave conductor NbSe3

2004 ◽  
Vol 114 ◽  
pp. 135-136 ◽  
Author(s):  
E. Slot ◽  
K. O'Neill ◽  
H. S.J. van der Zant ◽  
R. E. Thorne
Keyword(s):  
Charge Density ◽  
Charge Density Wave ◽  
Density Wave ◽  
Tunneling Spectroscopy

Tunneling spectroscopy of quasi-two-dimensional plasmons

2001 ◽  
Vol 171 (12) ◽  
pp. 1368
Author(s):  
V.A. Volkov ◽  
E.E. Takhtamirov ◽  
D.Yu. Ivanov ◽  
Yu.V. Dubrovskii ◽  
L. Eaves ◽  
...  
Keyword(s):  
Tunneling Spectroscopy ◽  
Two Dimensional

Scanning-tunneling spectroscopy on conjugated polymer films

2003 ◽  
Vol 771 ◽  
Author(s):  
M. Kemerink ◽  
S.F. Alvarado ◽  
P.M. Koenraad ◽  
R.A.J. Janssen ◽  
H.W.M. Salemink ◽  
...  
Keyword(s):  
Polymer Films ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Field Enhancement ◽  
Direct Consequence ◽  
Scanning Tunneling Spectroscopy ◽  
Tunneling Spectroscopy ◽  
Band Alignment ◽  
Scanning Tunneling ◽  
Order Of Magnitude

AbstractScanning-tunneling spectroscopy experiments have been performed on conjugated polymer films and have been compared to a three-dimensional numerical model for charge injection and transport. It is found that field enhancement near the tip apex leads to significant changes in the injected current, which can amount to more than an order of magnitude, and can even change the polarity of the dominant charge carrier. As a direct consequence, the single-particle band gap and band alignment of the organic material can be directly obtained from tip height-voltage (z-V) curves, provided that the tip has a sufficiently sharp apex.

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