| 초록 |
Surface-enhanced spectrosopic techniques utilizing plasmonic nanostructures have succeeded in sensitive measurement of molecular signatures, and this surface enhancement scheme has also been applied to increase very weak intrinsic chiroptical signals of chiral molecules. Ultrasensitive chiral sensing of a minute amount of biomolecules using plasmonics were demonstrated with enhancement up to 6 orders of magnitude, but mechanism of this extreme enhancement is still controversial, because theoretical models could not explain such large enhancement. Theoretical study of surface-enhanced circular dichroism has been difficult beacuse description of chiral molecule is often too simplified. In this work, we present higher-order multipole transition allows extreme enhancemnt of circular dichroism, which could not be observed under dipole approximation. Such strong multipole transition is especially strong near plasmonic nano-antenna. |
