The response of gold nanoparticle dimers is studied theoretically near and beyond the limit where the particles are touching. As the particles approach each other, a dominant dipole feature is observed that is pushed into the infrared due to interparticle coupling and that is associated with a large pileup of induced charge in the interparticle gap. The redshift becomes singular as the particle...

by John G. Cramer Alternate View Column AV-150

Self-assembly of minimum-energy configurations of a two-dimensional system consisting of charged particles confined in a quadratic trap and interacting through competing repulsive and attractive interparticle forces is studied by means of molecular dynamics simulation. It is shown that complex configurations, including concentric shells separated by bandlike voids, connected shells with multipl...

Reversible self-assembly of nanoparticles into ordered structures is essential for both fundamental study and practical applications. Although extensive work has been conducted, the demand for simple, cheap, reversible, and versatile ordering methods is still a central issue in current nanoscience and nanotechnology. Here we report a reversible and precise self-assembly of nanoparticles through...

The contact dynamics method (CD) is an efficient simulation technique of dense granular media where unilateral and frictional contact problems for a large number of rigid bodies have to be solved. In this paper we present a modified version of the contact dynamics to generate homogeneous random packings of rigid grains. CD is coupled to an external pressure bath, which allows the variation of t...

Describing a potential energy surface in terms of local minima and the transition states that connect them provides a conceptual and computational framework for understanding and predicting observable properties. Visualizing the potential energy landscape using disconnectivity graphs supplies a graphical connection between different structure-seeking systems, which can relax efficiently to a pa...

We consider a classical system of n charged particles confined by an external potential in any dimension d bigger than 2. The particles interact via pairwise repulsive Coulomb forces and the pair-interaction strength scales as the inverse of n (mean-field regime). The goal is to investigate the microscopic structure of the minimizers. It has been proved by Sandier-Serfaty (d=2) and Rougerie-Ser...

We present a coarse-graining model that enables the description of pressure-induced, endothermic reactions in a model material. An additional implicit variable (the particle size) is used to describe particles undergoing volume-reducing endothermic reactions via a bistable intra-molecular potential, whereas the dynamics of the centerof-mass motion evolves according to interparticle forces. The ...

We present a theoretical expression for the acoustic interaction force between small spherical particles suspended in an ideal fluid exposed to an external acoustic wave. The acoustic interaction force is the part of the acoustic radiation force on one given particle involving the scattered waves from the other particles. The particles, either compressible liquid droplets or elastic microsphere...