Chi-Hang Lam

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We study the morphological evolution of strained heteroepitaxial films using kinetic Monte Carlo simulations in two dimensions. A novel Green's function approach, analogous to boundary integral methods, is used to calculate elastic energies efficiently. We observe island formation at low lattice misfit and high temperature that is consistent with the(More)
Most polymers solidify into a glassy amorphous state, accompanied by a rapid increase in the viscosity when cooled below the glass transition temperature (T(g)). There is an ongoing debate on whether the T(g) changes with decreasing polymer film thickness and on the origin of the changes. We measured the viscosity of unentangled, short-chain polystyrene(More)
We study the morphological evolution of strained heteroepitaxial films using a kinetic Monte Carlo method in three dimensions. The elastic part of the problem uses a Green's function method. Isolated islands are observed under deposition conditions for deposition rates slow compared with intrinsic surface roughening rates. They are hemispherical and(More)
  • Chi-Hang Lam
  • Physical review. E, Statistical, nonlinear, and…
  • 2010
A solid-on-solid model is generalized to study the formation of Ge pyramid islands bounded by (105) facets on Si(100) substrates in two dimensions. Each atomic column is not only characterized by the local surface height but also by two deformation state variables dictating the local surface tilt and vertical extension. These local deformations(More)
Accelerated algorithms for simulating the morphological evolution of strained heteroepitaxy based on a ball and spring lattice model in three dimensions are explained. We derive exact Green’s function formalisms for boundary values in the associated lattice elasticity problems. The computational efficiency is further enhanced by using a superparticle(More)
the surface fluctuations Zhaohui Yang, Chi-Hang Lam, Elaine DiMasi, Nathalie Bouet, Jean Jordan-Sweet, and Ophelia K. C. Tsui Department of Physics, Boston University, Boston, Massachusetts 02215, USA Department of Applied Physics, Hong Kong Polytechnic University, Hung Hom, Hong Kong National Synchrotron Light Source, Brookhaven National Laboratory, Upton,(More)
A competitive growth model (CGM) describes the aggregation of a single type of particle under two different growth rules with occurrence probabilities p and 1-p . We explain the origin of the scaling behavior of the resulting surface roughness at small p for two CGM's which describe random deposition (RD) competing with ballistic deposition and RD competing(More)