Vibrations of coupled nanoparticules

Description

This page presents the vibration eigenmodes of two identical elastically-isotropic silver spheres (diameters 10 nm) whose centers are 9 nm apart. The overlapping of the two spheres ensure a mechanical coupling.

• Modes 0 to 5 are the 6 zero-frequency rigid body translations and rotations. They are not shown here.
• Irreducible representations were determined according to the character table for the D_∞h point group (for example, see here). Raman active modes are colored.
• The last column contains the single nanoparticle eigenmode which contribute the most to the vibration. See Lamb's model. The first letter is S or T for spheroidal or torsional respectively. The first subscript correspond to the angular momentum ℓ. The second one corresponds to its projection m onto the z direction (the direction going through the center of both spheres).
• Only one animation per line is shown even for E modes which have degeneracy 2. The other animation is obtained by switching the displacements along the directions perpendicular to the axis of symetry (red and green arrows).

See: Vibrations of weakly-coupled nanoparticles, L. Saviot & D. B. Murray, Phys. Rev. B 81, 235432 (2010) ( doi: 10.1103/PhysRevB.81.235432, 0912.1743 )