We investigate the spin-orbit induced spin-interference pattern of ballistic
electrons travelling along any regular polygon. It is found that the
spin-interference depends strongly on the Rashba and Dresselhaus spin-orbit
constants as well as on the sidelength and alignment of the polygon. We derive
the analytical formulae for the limiting cases of either zero Dresselhaus or
zero Rashba spin-orbit coupling, including the result obtained for a circle. We
calculate the nonzero Dresselhaus and Rashba case numerically for the square,
triangle, hexagon, and circle and discuss the observability of the
spin-interference which can potentially be used to measure the Rashba and
Dresselhaus coefficients.Comment: 17 pages, 4 figure