https://doi.org/10.1140/epjb/e2008-00339-x
Threshold field in nucleation process for an inhomogeneous deformable nonlinear Klein-Gordon system
1
Laboratoire de Mécanique, Département de Physique, Faculté des Sciences, Université de Yaoundé I., BP 812, Yaoundé, Cameroun
2
The Abdus Salam International Centre for Theoretical Physics, Strada Costiera, 34014 Trieste, Italy
3
Laboratoire de Mécanique et de Modélisation des systèmes Physiques (L2MSP),
Université de Dschang, BP 67, Dschang, Cameroun
Corresponding author: a rwoulach@uycdc.uninet.cm
Received:
3
December
2007
Revised:
4
June
2008
Published online:
8
September
2008
We investigate the effect of local inhomogeneity on the nucleation process of kink-antikink pairs in the driven nonlinear Klein-Gordon model with the Remoissenet-Peyrard substrate potential, whose shape can be varied as a function of the shape parameter and which has the sine-Gordon shape as a particular case. From numerical integrations of the model equations under defined conditions, the configuration of the critical nucleus in the presence of a localized inhomogeneity is determined and shown to be affected by the shape parameter of the substrate potential. The expression of the depinning threshold field of kink-antikink pairs, which is the value of the applied field at which the process of the nucleation of kink-antikink pairs takes place, is also obtained. The dependence of this depinning threshold field on the shape parameter r shows that it strongly increases, for small intensity of the impurity potential when the shape of the substrate potential deviates from the sinusoidal one.
PACS: 82.40.Ck – Pattern formation in reactions with diffusion, flow and heat transfer / 45.05.+x – General theory of classical mechanics of discrete systems / 87.10.+e – General theory and mathematical aspects
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2008
