Bloch-oscillations of exciton-polaritons and photons for the generation   of an alternating terahertz spin current
  We analyze theoretically the spin dynamics of exciton-polaritons and photons during their Bloch oscillations in a one-dimensional microwire. The wire geometry induces an energy splitting between the longitudinal and transverse electric polarized eigenmodes. We show analytically that a synchronized regime between the Bloch oscillations in space and the precession of the pseudospin can be achieved. This synchronization results in the formation of a THz alternating spin current which can be extracted out of the confinement region by the Landau-Zener tunneling towards the second allowed miniband. Finally we show how the spin signal can be maintained despite of the lifetime of the particles for the case of exciton-polaritons both in a resonant and non resonant pumping schemes. The structure therefore acts as a Spin-optronic device able to convert the polarization and emit spin polarized pulses. 
Hugo Flayac, Dmitry Solnyshkov and Guillaume Malpuech
cond-mat.mes-hall cond-mat.other