Topological surface states in the Kondo insulator YbB12 revealed via planar tunneling spectroscopy

被引：3

作者：

Gupta, A. ^{[1
,2
]}

Weiser, A. ^{[3
]}

Pressley, L. ^{[4
,5
,9
]}

Luo, Y. ^{[4
,5
]}

Lygouras, C. ^{[4
,5
]}

Trowbridge, J. ^{[6
]}

Phelan, W. A. ^{[4
,5
,6
,7
,10
]}

Broholm, C. L. ^{[4
,5
]}

McQueen, T. M. ^{[4
,5
,6
,8
]}

Park, W. K. ^{[1
]}

机构：

[1] Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA

[2] Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA

[3] Youngstown State Univ, Dept Phys Astron Geol & Environm Sci, Youngstown, OH 44555 USA

[4] Johns Hopkins Univ, Inst Quantum Matter, Baltimore, MD 21218 USA

[5] Johns Hopkins Univ, William H Miller III Dept Phys & Astron, Baltimore, MD 21218 USA

[6] Johns Hopkins Univ, Dept Chem, Baltimore, MD 21218 USA

[7] Johns Hopkins Univ, Hopkins Extreme Mat Inst, Baltimore, MD 21218 USA

[8] Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA

[9] Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA

[10] Los Alamos Natl Lab, Mail Stop E574, Los Alamos, NM 87545 USA

来源：

PHYSICAL REVIEW B | 2023年 / 107卷 / 16期

关键词：

SINGLE DIRAC CONE; SPIN; GAP;

D O I：

10.1103/PhysRevB.107.165132

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Planar tunneling spectroscopy of the Kondo insulator SmB6 suggests that an interaction between the surface Dirac fermions and the bulk spin excitons results in incompletely protected topological surface states. To gain further insight into their true nature, it is necessary to study other topological Kondo insulator candidates. Calculations of electronic energy bands predict that the Kondo insulator YbB12 hosts topological surface states protected by crystalline mirror symmetry. In this study, we present tunneling conductance spectra obtained from the (001) surface of YbB12 single crystals and discuss them in comparison to SmB6. The linear conductance at low bias provides strong evidence for the existence of surface Dirac fermions. The double-hump structure in the negative-bias region is associated with hybridized band edges, in agreement with a calculated band structure. While these similarities with SmB6 are suggestive of the existence of topological surface states in YbB12, in agreement with other experiments, some discrepancies are also observed, which we attribute to a difference in their exact nature from those in SmB6.

引用

页数：10