Spin response to localized pumps : exciton polaritons versus electrons and holes
Sacksteder IV, Vincent
Pervishko, Anastasiia A.
Shelykh, Ivan A.
Date of Issue2016
School of Physical and Mathematical Sciences
Polariton polarization can be described in terms of a pseudospin which can be oriented along the x,y, or z axis, similarly to electron and hole spin. Unlike electrons and holes where time-reversal symmetry requires that the spin-orbit interaction be odd in the momentum, the analog of the spin-orbit interaction for polaritons, the so-called TE-TM splitting, is even in the momentum. We calculate and compare spin transport of polariton, electron, and hole systems, in the diffusive regime of many scatterings. After dimensional rescaling diffusive systems with spatially uniform particle densities have identical dynamics, regardless of the particle type. Differences between the three particles appear in spatially nonuniform systems, with pumps at a specific localized point. We consider both oscillating pumps and transient (delta function) pumps. In such systems each particle type produces distinctive spin patterns. The particles can be distinguished by their differing spatial multipole character, their response and resonances in a perpendicular magnetic field, and their relative magnitude which is largest for electrons and weakest for holes. These patterns are manifested both in response to unpolarized pumps which produce in-plane and perpendicular spin signals, and to polarized pumps where the spin precesses from in-plane to out-of-plane and vice versa. These results will be useful for designing systems with large spin polarization signals, for identifying the dominant spin-orbit interaction and measuring subdominant terms in experimental devices, and for measuring the scattering time and the spin-orbit coupling's magnitude.
Physical Review B
© 2016 American Physical Society (APS). This paper was published in Physical Review B and is made available as an electronic reprint (preprint) with permission of American Physical Society (APS). The published version is available at: [http://dx.doi.org/10.1103/PhysRevB.93.085311]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.