Screening and strain effects on the ground-state energy of a quasi-two-dimensional quantum well system

Abstract

We discuss the screening and strain effects on the ground-state energy of the strained-layer semiconductor quantum wells, which forms a quasi-two-dimensional electron-hole plasma within the screened Hartree-Fock approximation. The exchange self-energy is evaluated within the Thomas-Fermi screening scheme for variation of the sheet density and the biaxial compressive strain. Such evaluation includes the solving of the Luttinger-Kohn Hamiltonian, which leads to obtaining the valence band structure [Phys. Rev. 97, 869 (1955)]. The dependence of the exchange self-energy on the sheet density and the strain is shown to be significantly reduced as the screening effects are taken into account. Also, the screening plays an important role in determining the ground-state energy and the renormalization of the single-particle energies. In addition, we observe that the ground-state energy increases with the biaxial compressive strain.