Optical anisotropy of InAs/GaSb broken-gap quantum wells

• Published in: Journal of experimental and theoretical physics Vol. 114; no. 5; pp. 731 - 737
• Main Authors: Zakharova, A. A., Semenikhin, I. A., Chao, K. A.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.05.2012; Springer
• Subjects: ABSORPTION; Analysis; ANISOTROPY; Atoms; Classical and Quantum Gravitation; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Elementary Particles; ENERGY LEVELS; Fysik; GALLIUM ANTIMONIDES; HAMILTONIANS; INDIUM ARSENIDES; INTERFACES; L-S COUPLING; MATRIX ELEMENTS; Molecules; NANOSCIENCE AND NANOTECHNOLOGY; Natural Sciences; Naturvetenskap; Optics; Particle and Nuclear Physics; Physical Sciences; Physics; Physics and Astronomy; POISSON EQUATION; POLARIZATION; Quantum Field Theory; QUANTUM WELLS; Relativity Theory; Solid State Physics; STRAINS; SYMMETRY BREAKING; TECHNOLOGY; TEKNIKVETENSKAP; VISIBLE RADIATION; WAVE FUNCTIONS; WAVE PROPAGATION; GaSb; GaSb Layer; AlSb; Optical Anisotropy; Spin Splitting
• ISSN: 1063-7761; 1090-6509; 1090-6509
• DOI: 10.1134/S1063776112030090

We investigate in detail the optical anisotropy of absorption of linearly polarized light in InAs/GaSb quantum wells grown on GaSb along the [001] direction, which can be used as an active region of different laser structures. The energy level positions, the wave functions, the optical matrix elements, and the absorption coefficients are calculated using the eight-band k · p model and the Burt-Foreman envelope function theory. In these calculations, the Schrödinger and Poisson equations are solved self-consistently taking the lattice-mismatched strain into account. We find that a realistic Hamiltonian, which has the C 2 v symmetry, results in considerable anisotropy of optical matrix elements for different directions of light polarization and different directions of the initial-state in-plane wave vector, including low-symmetry directions. We trace how the optical matrix elements and absorption are modified when spin-orbit interaction and important symmetry breaking mechanisms are taken into account (structural inversion asymmetry, bulk inversion asymmetry, and interface Hamiltonian). These mechanisms result in an almost 100% anisotropy of the absorption coefficients as the light polarization vector rotates in the plane of the structure and in a plane normal to the interfaces.