TY - JOUR
T1 - Signature of band inversion in the perovskite thin-film alloys BaS n1-x P bx O3
AU - Shiogai, Junichi
AU - Chida, Takumaru
AU - Hashimoto, Kenichiro
AU - Fujiwara, Kohei
AU - Sasaki, Takahiko
AU - Tsukazaki, Atsushi
N1 - Funding Information:
In conclusion, we have investigated the optical conductivity and electrical magnetotransport properties of PLD-grown BaS n 1 − x P b x O 3 thin films to exemplify TPT from the band insulator BaSn O 3 to the semimetal BaPb O 3 . We have observed an insulator-to-metal transition in both the optical conductivity spectra and the temperature dependence of the resistivity. An anomalous suppression of the optical and electrical conductivities at a critical x = 0.9 constitutes persuasive evidence of a small Fermi surface, which directly links to the electronic band modification with a band inversion. This conclusion is also supported by the enhanced spin-orbit magnetic field extracted from the low-field magnetoconductance. The intriguing anomaly of the electronic structure associated with the band-gap modification presented in this paper can be explored by more direct ways such as electrical transport measurements in mesoscopic wires [3] or in field-effect transistor configurations with electrostatic tuning of the Fermi level, and angle-resolved photoemission spectroscopy measurements [1,4–6] . Our findings provide a platform for investigating topological features combined with a wide variety of physical properties inherent in perovskite oxide materials.
Funding Information:
We thank Hidenori Takagi for fruitful discussions and Yuka Ikemoto and Taro Moriwaki for technical assistance. Far-infrared reflectivity measurements using a synchrotron radiation light source were performed at SPring-8 with the approval of the Japan Synchrotron Radiation Research Institute (Grant No. 2018B0073). This work was supported by Grants-in-Aid for Scientific Research (Grants No. 15H05699, No. JP15H05853, and No. 16H05981) from the Japan Society for the Promotion of Science and CREST (Grant No. JPMJCR18T2), the Japan Science and Technology Agency. Chemical composition analysis was performed under the Inter-University Cooperative Research Program of the Institute for Materials Research, Tohoku University.
PY - 2020/3/15
Y1 - 2020/3/15
N2 - Perovskite oxides ABO3 containing heavy B-site elements are a class of candidate materials to host topological metals with a large spin-orbit interaction. In contrast to the band insulator BaSnO3, the semimetal BaPbO3 is proposed to be a typical example with an inverted band structure, the conduction band of which is composed of mainly the O-2p orbital. In this paper, we exemplify a band-gap modification by systematic structural, optical, and transport measurements in BaSn1-xPbxO3 films. A sudden suppression of the conductivity and an enhancement of the weak antilocalization effect at x=0.9 indicate the presence of a singular point in the electronic structure as a signature of the band inversion. Our findings provide an intriguing platform for combining topological aspects and electron correlation in perovskite oxides based on band-gap engineering.
AB - Perovskite oxides ABO3 containing heavy B-site elements are a class of candidate materials to host topological metals with a large spin-orbit interaction. In contrast to the band insulator BaSnO3, the semimetal BaPbO3 is proposed to be a typical example with an inverted band structure, the conduction band of which is composed of mainly the O-2p orbital. In this paper, we exemplify a band-gap modification by systematic structural, optical, and transport measurements in BaSn1-xPbxO3 films. A sudden suppression of the conductivity and an enhancement of the weak antilocalization effect at x=0.9 indicate the presence of a singular point in the electronic structure as a signature of the band inversion. Our findings provide an intriguing platform for combining topological aspects and electron correlation in perovskite oxides based on band-gap engineering.
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U2 - 10.1103/PhysRevB.101.125125
DO - 10.1103/PhysRevB.101.125125
M3 - Article
AN - SCOPUS:85083365908
VL - 101
JO - Physical Review B
JF - Physical Review B
SN - 2469-9950
IS - 12
M1 - 125125
ER -