Abrupt barrier contribution to electron spin splitting in asymmetric coupled double quantum wells

Abstract

We have studied the behavior of the electronic energy spin-splitting of InGaAs − InAlAs based double quantum wells (narrow gap structures) under in-plane magnetic and transverse electric fields. We have developed an improved 8 × 8 version of the Transfer Matrix Approach that consider contributions from abrupt interfaces and external fields when tunneling through central barrier exists. We have included the Landé g-factor dependence on the external applied field. Also, we have calculated electron density of states and photoluminescence excitation. Variations of the electron spin-splitting energy lead to marked peculiarities in the density of states.Because the density of states is directly related to photoluminescence excitation, these peculiarities are observable by this technique.

Intersubband optical absorption in InSb stepped quantum wells: Effect of spin sublevels crossing

“…The characteristic spin velocity for each layer is v eF m /4 g ε = μ μ μ ⊥ , with g ε μ the gap energy. After some heavy algebra [12], we obtain the fundamental solutions of Eq. (1) for spin ( , ) σ = ↑ ↓ : …”

“…x y = we introduce a modification of the method used before [12]. The total transfer matrix can be written as …”

“…In Eq. (12) μ is the permeability and ϵ is the permittivity of the wells (we take the same values for the two materials), c is the light speed in the vacuum, and V is the volume of the sample.…”

Intersubband optical absorption in InSb stepped quantum wells. Effect of spin sublevels crossing

“…The following step is to generate 4 × 4 Wronskian-like transfer matrices, M µ (L i , E, p), which involve contour conditions at interface L i . To obtain electronic levels for each 2D momentum p = (p x , p y ) we introduce a modification of the method used before [12]. The total transfer matrix can be written as:…”