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Terahertz conductivity of topological surface states in Bi1.5Sb0.5Te1.8Se1.2

หน่วยงาน Nanyang Technological University, Singapore

รายละเอียด

ชื่อเรื่อง : Terahertz conductivity of topological surface states in Bi1.5Sb0.5Te1.8Se1.2
นักวิจัย : Tang, Chi Sin , Xia, Bin , Zou, Xingquan , Chen, Shi , Ou, Hong-Wei , Wang, Lan , Rusydi, A. , Zhu, Jian-Xin , Chia, Elbert E. M.
คำค้น : DRNTU::Science::Chemistry::Biochemistry::Spectroscopy.
หน่วยงาน : Nanyang Technological University, Singapore
ผู้ร่วมงาน : -
ปีพิมพ์ : 2556
อ้างอิง : Tang, C. S., Xia, B., Zou, X., Chen, S., Ou, H.-W., Wang, L., et al. (2013). Terahertz conductivity of topological surface states in Bi1.5Sb0.5Te1.8Se1.2. Scientific Reports, 3, 3513. , 2045-2322 , http://hdl.handle.net/10220/18597 , http://dx.doi.org/10.1038/srep03513
ที่มา : -
ความเชี่ยวชาญ : -
ความสัมพันธ์ : Scientific reports
ขอบเขตของเนื้อหา : -
บทคัดย่อ/คำอธิบาย :

Topological insulators are electronic materials with an insulating bulk and conducting surface. However, due to free carriers in the bulk, the properties of the metallic surface are difficult to detect and characterize in most topological insulator materials. Recently, a new topological insulator Bi1.5Sb0.5Te1.7Se1.3 (BSTS) was found, showing high bulk resistivities of 1–10 Ω.cm and greater contrast between the bulk and surface resistivities compared to other Bi-based topological insulators. Using Terahertz Time-Domain Spectroscopy (THz-TDS), we present complex conductivity of BSTS single crystals, disentangling the surface and bulk contributions. We find that the Drude spectral weight is 1–2 orders of magnitude smaller than in other Bi-based topological insulators, and similar to that of Bi2Se3 thin films, suggesting a significant contribution of the topological surface states to the conductivity of the BSTS sample. Moreover, an impurity band is present about 30 meV below the Fermi level, and the surface and bulk carrier densities agree with those obtained from transport data. Furthermore, from the surface Drude contribution, we obtain a ~98% transmission through one surface layer — this is consistent with the transmission through single-layer or bilayer graphene, which shares a common Dirac-cone feature in the band structure.

NRF (Natl Research Foundation, S’pore)

MOE (Min. of Education, S’pore)

บรรณานุกรม :
Tang, Chi Sin , Xia, Bin , Zou, Xingquan , Chen, Shi , Ou, Hong-Wei , Wang, Lan , Rusydi, A. , Zhu, Jian-Xin , Chia, Elbert E. M. . (2556). Terahertz conductivity of topological surface states in Bi1.5Sb0.5Te1.8Se1.2.
    กรุงเทพมหานคร : Nanyang Technological University, Singapore.
Tang, Chi Sin , Xia, Bin , Zou, Xingquan , Chen, Shi , Ou, Hong-Wei , Wang, Lan , Rusydi, A. , Zhu, Jian-Xin , Chia, Elbert E. M. . 2556. "Terahertz conductivity of topological surface states in Bi1.5Sb0.5Te1.8Se1.2".
    กรุงเทพมหานคร : Nanyang Technological University, Singapore.
Tang, Chi Sin , Xia, Bin , Zou, Xingquan , Chen, Shi , Ou, Hong-Wei , Wang, Lan , Rusydi, A. , Zhu, Jian-Xin , Chia, Elbert E. M. . "Terahertz conductivity of topological surface states in Bi1.5Sb0.5Te1.8Se1.2."
    กรุงเทพมหานคร : Nanyang Technological University, Singapore, 2556. Print.
Tang, Chi Sin , Xia, Bin , Zou, Xingquan , Chen, Shi , Ou, Hong-Wei , Wang, Lan , Rusydi, A. , Zhu, Jian-Xin , Chia, Elbert E. M. . Terahertz conductivity of topological surface states in Bi1.5Sb0.5Te1.8Se1.2. กรุงเทพมหานคร : Nanyang Technological University, Singapore; 2556.