“…6,7 Several chiral molecular species including DNA, [8][9][10][11][12] oligopeptides, [13][14][15] bacteriorhodopsin (bR), 16,17 a chiral conductive polymer, 18 1, 2-diphenyl-1,2-ethanediol (DPED), 19 helicenes, 20 and recently chiral CdSe quantum dots 21 have demonstrated efficient spin filtering. The spin filtering ability can be tuned by various means, for example, by varying the length of the chiral molecule, 8,9,13 by exposure to light, 22 or by varying the temperature. 23 The sign of the favored spin can be reversed by light, as was shown for an oligopeptide-CdSe hybrid 22 and also by lowering the temperature, which causes cold denaturation of the peptide-made monolayers, as seen in an oligopeptide-CdSe hybrid studied in the Hall configuration.…”