Spin Hall Effect in ballistic two dimensional electron gases with spin-orbit coupling

ANDRES REYNOSO,; GONZALO USAJ; CARLOS BALSEIRO,

PHYSICAL REVIEW B - CONDENSED MATTER AND MATERIALS PHYSICS

Año: 2006 vol. 73 p. 115342 - 115342

0163-1829

We study the spin polarization induced by a current flow in clean two-dimensional electron gases with Rashba spin-orbit coupling. This geometric effect originates from special properties of the electron’s scattering at the edges of the sample. In wide samples, the spin polarization has its largest value at low energies close tothe bottom of the band and goes to zero at higher energies. In this case, the spin polarization is dominated by the presence of evanescent modes which have an explicit spin component outside the plane. In quantum wires, on the other hand, the spin polarization is dominated by interference effects induced by multiple scattering at the edges. Here, the spin polarization is quite sensitive to the value of the Fermi energy, especially close to the point where a new channel opens up. We analyzed different geometries and found that the spin polarization canbe strongly enhanced.