arXiv subjects

Xin Lin

Publications and source records attributed to Xin Lin.

128 records · Page 8Linked to original sources

arXiv2011

Orientation selection of equiaxed dendritic growth by three-dimensional cellular automaton model

A three-dimensional (3-D) adaptive mesh refinement (AMR) cellular automata (CA) model is developed to simulate the equiaxed dendritic growth of pure substance. In order to reduce the mesh induced anisotropy by CA capture rules, a limited neighbor solid fraction (LNSF) method is presented. An expansion description using two interface free energy anisotropy parameters (\epsilon1, \epsilon2) is used in present 3-D CA model. The dendrite growths with the orientation selection between <100> and <110> are discussed using the different \epsilon1 with \epsilon2=-0.02. It is found that the simulated morphologies by present CA model are as expected from the minimum stiffness criterion.

nlin.CG↗

arXiv2011

Gap opening of single-layer graphene under the continuum model

Gap opening at the Dirac point of the single-layer graphene with periodic scalar and vector potentials has been theoretically investigated under the continuum model. The symmetry analysis indicates that the two-fold degeneracy at the Dirac point can be lifted when the potentials break both the chiral symmetry and the time-reversal symmetry. A gap equation at the Dirac point is obtained analytically with perturbation theory. It is shown that a mass term at the Dirac point would be generated by coupling of vector and scalar potentials. This gap equation could be considered as a criterion for gap opening at the Dirac point, which is confirmed by the numerical calculation. Furthermore, the bandgap from the gap equation agrees well with the exact result, when the applied potentials are weak.

cond-mat.mes-hall↗