@article{oai:ynu.repo.nii.ac.jp:00009416,
 author = {Katayama, I. and Kawakami, H. and Hagiwara, T. and Arashida, Y. and Minami, Y and Nien, L.-W. and Handegard, O. S. and Nagao, T. and Kitajima, M. and Takeda, J.},
 issue = {21},
 journal = {Physical Review B},
 month = {Dec},
 note = {Terahertz-field-induced carrier generation processes were investigated in Dirac electron systems, single-crystalline bismuth antimony alloy thin films (Bi1−xSbx; 0≤x≤0.16). This investigation was performed by precisely tuning, via the substituent ratio x, the band structure of the films from that associated with a semimetal to that characteristic of a narrow-gap semiconductor. Terahertz-field-induced absorption was clearly observed within a few picoseconds after the terahertz pump-pulse illumination of Bi1−xSbx semimetal and semiconductor samples. The field-strength dependence of the induced absorption was compared with the calculated Zener tunneling probability in the Dirac-like band dispersion. Through this comparison, the mechanism of the induced absorption was attributed to the carrier generation via the terahertz-field-induced Zener tunneling. The tunneling occurred in subpicosecond timescales even at room temperature, demonstrating that Bi1−xSbx thin films are promising for future high-speed electronics and the investigation of universal ultrafast tunneling dynamics.},
 pages = {214302-1--214302-5},
 title = {Terahertz-field-induced carrier generation in Bi1−xSbx Dirac electron systems},
 volume = {98},
 year = {2018}
}