  Recent experiments have shown the potential of surface acoustic waves as a
mean for transporting charge and spin in quantum wells. In particular, they
have proven highly effective for the coherent transport of spin-polarized wave
packets, suggesting their potential in spintronics applications. Motivated by
these experimental observations, we have theoretically studied the spin and
charge dynamics in a quantum well under surface acoustic waves. We show that
the dynamics acquires a simple and transparent form in a reference frame
co-moving with the surface acoustic wave. Our results, e.g., the calculated
spin relaxation and precession lengths, are in excellent agreement with recent
experimental observations.
