TY - JOUR
T1 - Robust topological surface state in Kondo insulator SmB6 thin films
AU - Yong, Jie
AU - Jiang, Yeping
AU - Usanmaz, Demet
AU - Curtarolo, Stefano
AU - Zhang, Xiaohang
AU - Li, Linze
AU - Pan, Xiaoqing
AU - Shin, Jongmoon
AU - Takeuchi, Ichiro
AU - Greene, Richard L.
N1 - Publisher Copyright:
© 2014 AIP Publishing LLC.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - Fabrication of smooth thin films of topological insulators with true insulating bulk are extremely important for utilizing their novel properties in quantum and spintronic devices. Here, we report the growth of crystalline thin films of SmB6, a topological Kondo insulator with true insulating bulk, by co-sputtering both SmB6 and B targets. X-ray diffraction, Raman spectroscopy, and transmission electron microscopy indicate films that are polycrystalline with a (001) preferred orientation. When cooling down, resistivity ρ shows an increase around 50K and saturation below 10K, consistent with the opening of the hybridization gap and surface dominated transport, respectively. The ratio ρ2K/ρ300K is only about two, much smaller than that of bulk, which indicates a much larger surface-to-bulk ratio. Point contact spectroscopy using a superconductor tip on SmB6 films shows both a Kondo Fano resonance and Andeev reflection, indicating an insulating Kondo lattice with metallic surface states.
AB - Fabrication of smooth thin films of topological insulators with true insulating bulk are extremely important for utilizing their novel properties in quantum and spintronic devices. Here, we report the growth of crystalline thin films of SmB6, a topological Kondo insulator with true insulating bulk, by co-sputtering both SmB6 and B targets. X-ray diffraction, Raman spectroscopy, and transmission electron microscopy indicate films that are polycrystalline with a (001) preferred orientation. When cooling down, resistivity ρ shows an increase around 50K and saturation below 10K, consistent with the opening of the hybridization gap and surface dominated transport, respectively. The ratio ρ2K/ρ300K is only about two, much smaller than that of bulk, which indicates a much larger surface-to-bulk ratio. Point contact spectroscopy using a superconductor tip on SmB6 films shows both a Kondo Fano resonance and Andeev reflection, indicating an insulating Kondo lattice with metallic surface states.
UR - https://www.scopus.com/pages/publications/84914109383
U2 - 10.1063/1.4902865
DO - 10.1063/1.4902865
M3 - 文章
AN - SCOPUS:84914109383
SN - 0003-6951
VL - 105
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 22
M1 - 222403
ER -