arXiv subjects

R. H. Dong

Publications and source records attributed to R. H. Dong.

3 recordsLinked to original sources

arXiv2012

Creep motion of a domain wall in the two-dimensional random-field Ising model with a driving field

With Monte Carlo simulations, we study the creep motion of a domain wall in the two-dimensional random-field Ising model with a driving field. We observe the nonlinear fieldvelocity relation, and determine the creep exponent μ. To further investigate the universality class of the creep motion, we also measure the roughness exponent ζ and energy barrier exponent ψ from the zero-field relaxation process. We find that all the exponents depend on the strength of disorder.

cond-mat.dis-nn↗

arXiv2012

Hamiltonian equation of motion and depinning phase transition in two-dimensional magnets

Based on the Hamiltonian equation of motion of the $ϕ^4$ theory with quenched disorder, we investigate the depinning phase transition of the domain-wall motion in two-dimensional magnets. With the short-time dynamic approach, we numerically determine the transition field, and the static and dynamic critical exponents. The results show that the fundamental Hamiltonian equation of motion belongs to a universality class very different from those effective equations of motion.

cond-mat.dis-nn↗

arXiv2012

Critical domain-wall dynamics of model B

With Monte Carlo methods, we simulate the critical domain-wall dynamics of model B, taking the two-dimensional Ising model as an example. In the macroscopic short-time regime, a dynamic scaling form is revealed. Due to the existence of the quasi-random walkers, the magnetization shows intrinsic dependence on the lattice size $L$. A new exponent which governs the $L$-dependence of the magnetization is measured to be $σ=0.243(8)$.

cond-mat.stat-mech↗