Tunneling spectroscopic study of the topological Kondo insulator YbB12 using second harmonic measurements

Electronic transport and the magnetoresistance measurements of single crystals and microstructures on the Kondo Insulator YbB12 reveal the presence of topologically protected surface states, suggesting that YbB12 is a candidate material for being a topological Kondo insulator [1]. Planar tunneling spectroscopic studies on YbB12 also support the formation of TSS (Topological Surface States) in YbB12 as is seen in SmB6, but data suggest that exact nature of the YbB12 TSS is different from that in SmB6 [2].

Second harmonic measurement techniques provide higher resolution and cleaner planar tunneling spectra which help us to compare and contrast the electronic structure of these interesting materials. We will present planar tunneling spectroscopic data on YbB12 in the low temperature resistance plateau range and compare it to planar tunneling data taken on SmB6 [3].

[1] Y. Sato et al., J. Phys. D: Appl. Phys. 54, 404002 (2021).

[2] A. Gupta et al., Phys. Rev. B 107, 165132 (2023).

[3] Robert Huber et al, this conference.