Eur. Phys. J. B 28, 475-481 (2002)
https://doi.org/10.1140/epjb/e2002-00250-6

Electron energy state spin-splitting in 3D cylindrical semiconductor quantum dots

¹ National Nano Device Laboratories, Hsinchu 300, Taiwan
² Microelectronics and Information Systems Research Center, National Chiao Tung University, Hsinchu 300, Taiwan
³ Institute of Electronics, National Chiao Tung University, Hsinchu 300, Taiwan
⁴ Kiev Taras Shevchenko University, 01033, Kiev, Ukraine

Corresponding author: ^a ymli@cc.nctu.edu.tw

Received: 15 May 2001
Revised: 14 May 2002
Published online: 13 August 2002

Abstract

In this article we study the impact of the spin-orbit interaction on the electron quantum confinement for narrow gap semiconductor quantum dots. The model formulation includes: (1) the effective one-band Hamiltonian approximation; (2) the position- and energy-dependent quasi-particle effective mass approximation; (3) the finite hard wall confinement potential; and (4) the spin-dependent Ben Daniel-Duke boundary conditions. The Hartree-Fock approximation is also utilized for evaluating the characteristics of a two-electron quantum dot system. In our calculation, we describe the spin-orbit interaction which comes from both the spin-dependent boundary conditions and the Rashba term (for two-electron quantum dot system). It can significantly modify the electron energy spectrum for InAs semiconductor quantum dots built in the GaAs matrix. The energy state spin-splitting is strongly dependent on the dot size and reaches an experimentally measurable magnitude for relatively small dots. In addition, we have found the Coulomb interaction and the spin-splitting are suppressed in quantum dots with small height.