Cubic Dresselhaus Spin-Orbit Coupling in 2D Electron Quantum Dots

We study effects of the oft-neglected cubic Dresselhaus spin-orbit coupling (i.e., ∝p³) in GaAs/AlGaAs quantum dots. Using a semiclassical billiard model, we estimate the magnitude of the spin-orbit induced avoided crossings in a closed quantum dot in a Zeeman field. Using previous analyses based on random matrix theory, we calculate corresponding effects on the conductance through an open quantum dot. Combining our results with an experiment on an 8μm² quantum dot [D. M. Zumbühl , Phys. Rev. BPRBMDO0163-1829 72, 081305 (2005)10.1103/PhysRevB.72.081305] suggests that (1) the GaAs Dresselhaus coupling constant γ is approximately 9eVų, significantly less than the commonly cited value of 27.5eVų, and (2) the majority of the spin-flip effects can come from the cubic Dresselhaus term.