Spin-Orbit Coupling and Zero-Field Electron Spin Splitting in AlGaN/AlN/GaN Heterostructures with a Polarization Induced Two-Dimensional Electron Gas

摘要

We studied spin-orbit coupling in wurtzite Al{sub}xGa{sub}(1-x)N/AlN/GaN heterostructures with different Al concentrations using weak antilocalization measurements at 1.6K. Using the persistent photoconductivity effect we cover a carrier density range extending from 0.8×10{sup}12cm{sup}(-2) to 10.6×10{sup}12cm{sup}(-2). The zero-field electron spin-splitting energies extracted from the weak antilocalization measurements scaled with the Fermi wave-vector k{sub}F as 2(ak{sub}F+(γk{sub}F){sup}3) with effective linear and cubic spin-orbit parameters of α=5.13×10{sup}(-13)eV·m and γ=1.2×10{sup}(-13) eV·m{sup}3, respectively.