Magnetoresistance of a weakly disordered III-V semiconductor quantum well in a magnetic field parallel to interfaces

We have investigated the weak-localization effects on the magnetoresistance of a two-dimensional electron gas in a quantum well of a semiconductor with a zinc-blende crystal structure under a sufficiently weak magnetic field $H$ applied parallel to interfaces, so it interacts only with the electron spins due to the Zeeman term in the Hamiltonian. We found a positive magnetoresistance, which depends strongly on the crystal orientation of the well, and varies with the direction of the field depending on the relative strengths of the Rashba and Dresselhaus terms in the spin-orbit coupling. For a [001]-oriented well we found that the magnetic field destroys antilocalization when the Zeeman energy $g\mu H$ is larger than $({\tau }_{\phi }{\tau }_{\mathrm{so}}{)}^{-1/2}$, where ${\tau }_{\phi }$ is the inelastic dephasing time and ${\tau }_{\mathrm{so}}$ the spin-orbit relaxation time. On the other hand, in a symmetric [011]-oriented quantum well, the Zeeman interaction leads to a weak localization of electrons.