Spin precession due to spin-orbit coupling in a two-dimensional electron gas with spin injection via ideal quantum point contact

We present the analytical result of the expectation value of spin with respect to an arbitrarily spin-polarized electron state which is injected via an ideal quantum point contact into a semi-infinite two-dimensional electron gas confined in a [001]-grown quantum well. Both the Rashba and Dresselhaus spin-orbit couplings are taken into account. The spatial behaviors of the spin precession due to the Rashba term, the Dresselhaus term, and simultaneously both terms are analyzed. We demonstrate that the [110], [(1) over bar 10],[(11) over bar0], and [1(1) over bar 0] axes own invariant behavior of spin precession, which is the same as that due to the Rashba term.