Terahertz-Field-Induced Carrier Generation in Bi1-xSbx Dirac Electron Systems
Terahertz-Field-Induced Carrier Generation in Bi1-xSbx Dirac Electron Systems
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Bi1-xSbx 狄拉克电子系统中的太赫兹场感应载流子生成
DOI：
10.1103/physrevb.98.214302
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
and J. Takeda
中科院分区：
文献类型：
--
作者：
I. Katayama;H. Kawakami;T. Hagiwara;Y. Arashida;Y. Minami;L.-W. Nien;O. S. Handegard;T. Nagao;M. Kitajima;and J. Takeda
研究了太赫兹场诱导的狄拉克电子系统中的载流子产生过程，单晶铋锑合金薄膜（;）。这项调查是通过精确调谐，通过取代基的比例，从与半金属的窄隙半导体的特性的膜的能带结构。在太赫兹泵浦脉冲照射半金属和半导体样品后的几皮秒内，清晰地观察到太赫兹场诱导吸收。的诱导吸收的场强依赖性进行了比较与计算的齐纳隧穿概率在Dirac-like带色散。通过比较，将诱导吸收的机制归因于通过太赫兹场诱导的齐纳隧穿产生的载流子。即使在室温下，隧穿也发生在亚皮秒的时间尺度上，这表明薄膜在未来的高速电子学和普遍的超快隧穿动力学研究中是有希望的。
Terahertz-field-induced carrier generation processes were investigated in Dirac electron systems, single-crystalline bismuth antimony alloy thin films (;). This investigation was performed by precisely tuning, via the substituent ratio, 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 ofsemimetal 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 thatthin films are promising for future high-speed electronics and the investigation of universal ultrafast tunneling dynamics.