Figure 5. Hall voltage measurements at different temperatures and for different sizes of nanoparticles.

All measurements were performed at 300 K and at 120 K for devices of the type shown in Fig. 4, coated with 6 and 2 nm diameter CdSe nanoparticles that are attached to the GaN surface via NH₂-{Ala-Aib}₈-COCHNH₂CH₂PO₄H₂ or SHCH₂CH₂CO-{Ala-Aib}₅-COOH molecules, at a current of 10 μA. The devices were illuminated with a 2.3 mW, 514 nm laser. Three sets of devices were measured and the variation in the signal among them is about 10%. The signal observed corresponds to effective magnetic fields of 20, 16, -5, -18, 73, 36, -8 and -22 G for panels a,b,c,d,e,f,g and h, respectively. All plots are presented after subtracting a background signal, measured for the same devices but covered with the non-chiral 11-mercaptoundecylphosphoric acid (see Supplementary Fig. 8). Pink and light-blue areas correspond to ‘light on' and ‘light off' regimes, respectively.