Asymmetry Effects in Optical Properties of a Gold Nanotube

Abstract

Asymmetry effects in optical properties of an infinitely long gold nanotube is studied within the framework of the quasi-static approximation. In this way, incident, scattered and transmitted fields are represented with the appropriate electrostatic potentials in the cylindrical coordinates. The problem is investigated using a boundary-value approach. The expressions for the polarizability and dispersion of surface plasmons of the system are derived and numerical results, in the wavelength region 500 nm to 1000 nm, show that instead of the one well-known resonance peak of the nanotube, one pair of resonance peaks appear, as a result of the coupling between the dipole and quadrupole modes. Then, scattering, absorption and extinction widths of the system are formulated. Also, the effective dielectric function of a composite of aligned symmetry-broken gold nanotubes is presented.

Future Paths in Cryogenic Single-Molecule Fluorescence Spectroscopy

“…Furthermore, it was demonstrated that the narrow ZPL could be spectrally tuned by applying hydrostatic pressure or an external electric field via linear or quadratic Stark effect . Orrit’s group reported the Stark effect of single molecules in several guest–host systems. − One of the milestones in earlier single-molecule studies was the optical detection of the electron spin of a single pentacene molecule in a p -terphenyl crystal using combined optically detected magnetic resonance (ODMR) and single-molecule fluorescence spectroscopy , (Figure A and B). By applying a resonant microwave frequency and observing the change in the fluorescence signal of a single molecule, the transitions between different sublevels of a triplet state can be detected.…”