Plasmonic ratchet wheels: switching circular dichroism by arranging chiral nanostructures.
We demonstrate circular dichroism (CD) in the second harmonic generation (SHG) signal from chiral assemblies of G-shaped nanostructures made of gold. The arrangement of the G shapes is crucial since upon reordering them the SHG-CD effect disappears. Microscopy reveals SHG "hotspots" assemblies, which originate in enantiomerically sensitive plasmon modes, having the novel property of exhibiting a chiral geometry themselves in relation with the handedness of the material. These results open new frontiers in studying chirality.
Molecular Electronics and Photonics, INPAC, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium. v.k.valev@fys.kuleuven.be
V K
VK
Valev
N
N
Smisdom
A V
AV
Silhanek
B
B
De Clercq
W
W
Gillijns
M
M
Ameloot
V V
VV
Moshchalkov
T
T
Verbiest