1 / 19

Yosuke Harashima , Keith Slevin Department of Physics, Osaka University, Japan

Numerical analysis for the m etal-insulator transition in doped semiconductors using density functional theory in the local density approximation. Yosuke Harashima , Keith Slevin Department of Physics, Osaka University, Japan. Metal-insulator transition in doped semiconductors.

doris
Télécharger la présentation

Yosuke Harashima , Keith Slevin Department of Physics, Osaka University, Japan

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Numerical analysis for the metal-insulator transitionin doped semiconductorsusing density functional theory in the local density approximation Yosuke Harashima, Keith Slevin Department of Physics, Osaka University, Japan

  2. Metal-insulator transition in doped semiconductors • Disorder • Metal-insulator transition • Electron-electron interaction • ex. Critical exponent

  3. Impurity band for low concentration

  4. For high concentration

  5. Model • Donor impurities distributed randomly in space • Long range Coulomb interaction for electron-electron pairs

  6. Schrödinger equation for impurity band • = 0.32 • = 12.0

  7. Kohn-Sham equations • Auxiliary system:

  8. Exchange-correlation energy in an effective medium

  9. Local density approximation

  10. Calculation details • Real space finite difference approximation • In this study M=2 and h=18[Bohr] • Complete spin polarized case (for simplicity)

  11. Multi-fractal analysis for Kohn-Sham orbital • A. Rodriguez et al (2011)

  12. Asymptotic behavior • Extended states: • Localized states:

  13. Metal-Insulator Transition around nD ≈ 1.5 [10-7 Bohr-3]

  14. Density of states • Periodic system • Disordered system

  15. nD ≈ 0.6 [10-7 Bohr-3]

  16. nD ≈ 1.4 [10-7 Bohr-3]

  17. nD ≈ 1.9 [10-7 Bohr-3]

  18. Summary • The model taking into account, • Random positions of impurities. • Electron-electron interaction using DFT in LDA. • The existence of the Metal-Insulator transition around nD ≈ 1.5 [10-7 Bohr-3] is shown in this model. • We are calculating the critical exponents. • As extension, • Spin of electrons using local spin density approximation. • Compensation of impurities.

More Related