Atomic collapse in pseudospin-1 systems

Chen Di Han, Hong Ya Xu, Danhong Huang, Ying-Cheng Lai

Research output: Contribution to journalArticle

Abstract

We investigate atomic collapse in pseudospin-1 Dirac material systems whose energy band structure constitutes a pair of Dirac cones and a flat band through the conic intersecting point. We obtain analytic solutions of the Dirac-Weyl equation for the three-component spinor in the presence of a Coulomb impurity and derive a general criterion for the occurrence of atomic collapse in terms of the normalized strength of Coulomb interaction and the angular momentum quantum number. In particular, for the lowest angular momentum state, the solution coincides with that for pseudospin-1/2 systems, but with a reduction in the density of resonance peaks. For higher angular momentum states, the underlying pseudospin-1 wave functions exhibit a singularity at the point of zero kinetic energy. Divergence of the local density of states associated with the flat band leads to an inverse square type of singularity in the conductivity. These results provide insights into the physics of the two-body problem for relativistic quantum pseudospin-1 quasiparticle systems.

Original languageEnglish (US)
Article number245413
JournalPhysical Review B
Volume99
Issue number24
DOIs
StatePublished - Jun 17 2019

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Angular momentum
angular momentum
Band structure
two body problem
Dirac equation
Wave functions
Coulomb interactions
Kinetic energy
quantum numbers
energy bands
Cones
divergence
cones
Physics
kinetic energy
wave functions
occurrences
Impurities
impurities
conductivity

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Atomic collapse in pseudospin-1 systems. / Han, Chen Di; Xu, Hong Ya; Huang, Danhong; Lai, Ying-Cheng.

In: Physical Review B, Vol. 99, No. 24, 245413, 17.06.2019.

Research output: Contribution to journalArticle

Han, Chen Di ; Xu, Hong Ya ; Huang, Danhong ; Lai, Ying-Cheng. / Atomic collapse in pseudospin-1 systems. In: Physical Review B. 2019 ; Vol. 99, No. 24.
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