Magnetotunneling of holes through single and double barriers using a multiband treatment

Abstract

We investigate tunneling of holes through a single barrier which is subject to an in-plane magnetic field. Band mixing between heavy and light holes is pronounced which indicates the necessity of using a multiband approach. The problem is investigated within the 4 ϫ 4 Luttinger-Kohn model for bands at ⌫ 8 , without restriction on the Luttinger parameters. The application of a magnetic field enhances the anisotropy in the transmission coefficients T ͑k x , k y ͒ and makes transitions possible between various channels ͑e.g., the two light holes͒. It is shown that heavy holes can precess when magnetic field is in plane, since band mixing lifts the selection rules for angular momentum. The current density is calculated for a double-barrier resonant structure and compared with a previous approximate theoretical result. This comparison clearly indicates that full wave vector dependence of the tunneling process is needed in order to obtain reliable values for the current.

Spin-dependent tunneling in diluted magnetic semiconductor trilayer structures

“…Holes in III-V semiconductors have angular momentum l = 1, so that, in the absence of external fields, there are three doubly degenerate bands: heavy hole ͑HH͒ band, light hole ͑LH͒ band, and split-off ͑SO͒ band. While in nonmagnetic GaAs/ AlAs heterostructures it is still possible to neglect the SO band ͑⑀ F ӷ⌬ SO ͒ and use the 4 ϫ 4 LK, 17 the inclusion of all three bands is necessary in DMS since the spin-splitting of holes is comparable with ⌬ SO . The Hamiltonian with exchange reads…”