Dependence of spin–orbit parameters in AlGaN/GaN quantum wells on the ratio of height between the left and right barrier

In AlGaN/GaN asymmetric QWs, the calculated Rashba parameters and the Rashba spin splitting increase linearly with the symmetry parameter σ (the ratio of height between the left and the right barrier), while the intersubband spin–orbit (SO) parameter decreases with σ increasing from 0.4 to 1.4. The dominant contribution to the SO parameters is from the well, next comes the contribution of the heterointerface, and they both increase with σ, since the expansion region of the envelope functions decreases and the average electric field in the well increases. What is more, the strong polarization electric field and high density of 2DEG in III-nitrides heterostructures make the Rashba spin splitting in AlGaN/GaN QWs comparable to that of narrow-gap III–V materials. The results indicate the SO parameters are sensitive to σ, which show the possible application of the III-nitrides in tunable spintronic devices.