Figure 1
From: Polarized recombination of acoustically transported carriers in GaAs nanowires
Experimental setup. (a) Experimental setup: the nanowire is excited by a tightly focused pulsed laser beam at the edge of the nanowire facing the interdigital transducer (excitation spot G) used for SAW generation. The PL signal emitted along the nanowire axis is split by a birefringence prism into two orthogonally polarized rays. The rays with polarization parallel (∥) and perpendicular (⊥) to the nanowire axis are detected on the upper and lower regions of the CCD images, respectively. (b) Schematic diagram of the spin transport measurements. Linear polarized light is converted into circularly polarized by a λ/4 plate, which allows to excite holes and electrons with one preferential spin polarization [spin-up (σ+) or spin-down (σ−)].