Volume 123, Issue 15, 15 October 2005
Index of content:
123(2005); http://dx.doi.org/10.1063/1.2071947View Description Hide Description
Electronic tunneling in a complex molecular network of donor/acceptor sites, connected by molecular bridges, is analyzed. The “deep” tunnelingdynamics is formulated using a recursive perturbation expansion, yielding a McConnell-type reduced -level model Hamiltonian. Applications to models of molecular junctions demonstrate that the donor-bridge contact parameters can be tuned in order to control the tunnelingdynamics and particularly to direct the tunneling pathway to either one of the various acceptors.
123(2005); http://dx.doi.org/10.1063/1.2085147View Description Hide Description
The thermodynamic and kinetic behaviors for solid superheating and liquid supercooling were critically examined and compared via molecular-dynamics simulations. It is shown that the large elastic energy associated with internal melting and solid-liquidinterface disorder play important roles in superheating. The growth rate is anisotropic for supercooling, but isotropic for superheating. Supercooling can be well described by the classical nucleation theory, whereas superheating shows many exceptions. The underlying mechanisms for these differences are discussed.