Terahertz-driven hot Dirac fermion and plasmon dynamics in the bulk-insulating topological insulator Bi2Se3

Bumjoo Lee, Chihun In, Jisoo Moon, Tae Hoon Kim, Seongshik Oh, Tae Won Noh, Hyunyong Choi

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


For degenerately doped three-dimensional topological insulators (3D TIs), the interaction dynamics between Dirac fermions and collective charge oscillations (plasmons) are considerably complicated. In particular, the low-energy contribution near band inversion is largely obscure because of the bulk-surface interaction as well as the two-dimensional electron gas (2DEG). We have circumvented these issues by performing high-field terahertz (THz) pump-probe spectroscopy in bulk insulating Bi2Se3 TI microribbon array structures. Plasmon blueshift of 11% was found to occur within 4 ps under 0.433 MV/cm THz excitation compared to the near-equilibrium state. Although the conventional optical pump or engineered microribbon TIs exhibits a similar plasmon blueshift, our observation is readily explained by the intrinsic plasmon behavior from the increased electronic temperature (Te≅1430K) and reduced chemical potential (μ≅16meV) without considering extrinsic contributions. Our findings may apply to other classes of Dirac materials to investigate the coupled low-energy interactions with collective quasiparticles.

Original languageEnglish
Article number045307
JournalPhysical Review B
Issue number4
Publication statusPublished - 2022 Jan 15

Bibliographical note

Funding Information:
B.L., and T.W.N. are supported by the Institute for Basic Science (IBS) in Korea (Grant No. IBS-R009-D1). C.I., T.H.K., and H.C. are supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (Ministry of Education, Science and Technology (MEST) and Ministry of Science and ICT (MSIT), South Korea) (Grants No. 2018R1A2A1A05079060, No. 2019R1A6A1A10073437, No. 2020M3F3A2A03082472, and No. 2021R1A2C3005905), Creative Materials Discovery Program (Grant No. 2017M3D1A1040828), Scalable Quantum Computer Technology Platform Center (Grant No. 2019R1A5A1027055), and Institute for Basic Science in Korea (Grant No. IBS-R014-G1-2018-A1). H.C. was supported by the New Faculty Startup Fund from Seoul National University. J.M. and S.O. were supported by MURI W911NF2020166 and the National Science Foundation (NSF) (Grant No. DMR2004125).

Publisher Copyright:
© 2022 American Physical Society.

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


Dive into the research topics of 'Terahertz-driven hot Dirac fermion and plasmon dynamics in the bulk-insulating topological insulator Bi2Se3'. Together they form a unique fingerprint.

Cite this