TY - JOUR
T1 - Unveiling quasiparticle dynamics of topological insulators through Bayesian modelling
AU - Tokuda, Satoru
AU - Souma, Seigo
AU - Segawa, Kouji
AU - Takahashi, Takashi
AU - Ando, Yoichi
AU - Nakanishi, Takeshi
AU - Sato, Takafumi
N1 - Funding Information:
This work was supported by JST-CREST (no. JPMJCR18T1), Grant-in-Aid for Scientific Research on Innovative Areas “Topological Materials Science” (JSPS KAKENHI Grant number JP15H05853), Grant-in-Aid for Scientific Research on Innovative Areas “Discrete Geometric Analysis for Materials Design” (JSPS KAKENHI Grant number JP18H04472), and Grant-in-Aid for Early-Career Scientists (JSPS KAKENHI Grant number 20K19889). The work in Cologne was funded by the Deutsche For-schungsgemeinschaft (German Research Foundation) - Project number 277146847 - CRC 1238 (Subproject A04).
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - 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.
AB - 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.
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U2 - 10.1038/s42005-021-00673-6
DO - 10.1038/s42005-021-00673-6
M3 - Article
AN - SCOPUS:85112073345
SN - 2399-3650
VL - 4
JO - Communications Physics
JF - Communications Physics
IS - 1
M1 - 170
ER -