Spin superfluidity of exciton polaritons in microcavities

Summary form only given. Conventional spintronics uses the charged quasiparticles (electrons or hole) as spin carriers. Dephasing of spin currents in electronic systems is very fast, and propagation of a spin current in metal over more than 1 micron is extremely hard to achieve. On the other hand, electrically neutral spin carriers, exciton-polaritons, are known to propagate ballistically over tens and hundreds of microns. This is why the optically mediated spintronics is extremely promising for spin processing. Exciton polaritons in microcavities obey the bosonic statistics and exhibit superfluid properties. The spin current carried by a polariton superfluid would show no dissipation and no spin relaxation. Various coherent effects are expected, including the spin Meissner, spin Josephson and spin Aaronov-Bohm effects.