セガワ コウジ   SEGAWA KOJI
  瀬川 耕司
   所属   京都産業大学  理学部 物理科学科
   職種   教授
発行・発表の年月 2021/12
形態種別 研究論文
標題 Unveiling quasiparticle dynamics of topological insulators through Bayesian modelling
執筆形態 その他
掲載誌名 Communications Physics
出版社・発行元 Springer Science and Business Media LLC
巻・号・頁 4(1)
著者・共著者 Satoru Tokuda,Seigo Souma,Kouji Segawa,Takashi Takahashi,Yoichi Ando,Takeshi Nakanishi,Takafumi Sato
概要 <title>Abstract</title>Quasiparticle - a key concept to describe interacting particles - characterizes electron-electron interaction in metals (Fermi liquid) and electron pairing in superconductors. While this concept essentially relies on the simplification of hard-to-solve many-body problem into one-particle picture and residual effects, a difficulty in disentangling many-body effects from experimental quasiparticle signature sometimes hinders unveiling intrinsic low-energy dynamics, as highlighted by the fierce controversy on the origin of Dirac-band anomaly in graphene and dispersion kink in high-temperature superconductors. Here, we propose an approach to solve this fundamental problem - the Bayesian modelling of quasiparticles. We have chosen a topological insulator TlBi(S,Se)2 as a model system to formulate an inverse problem of quasiparticle spectra with semiparametric Bayesian analysis, and successfully extracted one-particle and many-body characteristics, i.e. the intrinsic energy gap and unusual lifetime in Dirac-quasiparticle bands. Our approach is widely applicable to clarify the quasiparticle dynamics of quantum materials.
DOI 10.1038/s42005-021-00673-6
ISSN /2399-3650
PermalinkURL http://www.nature.com/articles/s42005-021-00673-6.pdf
researchmap用URL http://www.nature.com/articles/s42005-021-00673-6