By means of an extended variational approach,we study dynamics for gap solitons in a repulsive interactionBose-Einstein condensate under both a harmonic and an optical lattice confinement.The simplified analytic theor...By means of an extended variational approach,we study dynamics for gap solitons in a repulsive interactionBose-Einstein condensate under both a harmonic and an optical lattice confinement.The simplified analytic theorygives the critical strength ratio of harmonic to optical lattice necessary to support multiple stable lattice sites for thecondensate.Moreover,we use numerical experiments to guide and manipulate the gap solitons to an arbitrary positionvia a time-dependent potential.All predictions of the extended variational approach are reasonably close to results ofthe simulations.In particular,the variational model helps capture the composition relationship between the variationsof chirp and amplitude.展开更多
A high order finite difference scheme for solving the Regularised Long Wave(RLW) equation, based on the high order Pade approximation and Lax-Wendroff type timediscretization, was developed in this paper. Some numeric...A high order finite difference scheme for solving the Regularised Long Wave(RLW) equation, based on the high order Pade approximation and Lax-Wendroff type timediscretization, was developed in this paper. Some numerical examples, including the propagation of asingle soliton, the interaction of double solitary waves and the temporal evolution of a Maxwellianinitial pulse, were studied to test the accuracy, efficiency and conservation property of thescheme. Compared with the results based on finite element methods, the scheme is proven successful.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No. 10672147the Natural Science Foundation of Zhejiang Province, China under Grant Nos. Y605312, Y1080959the Department of Education Foundation of Zhejiang Province under Grant No. 20030704
文摘By means of an extended variational approach,we study dynamics for gap solitons in a repulsive interactionBose-Einstein condensate under both a harmonic and an optical lattice confinement.The simplified analytic theorygives the critical strength ratio of harmonic to optical lattice necessary to support multiple stable lattice sites for thecondensate.Moreover,we use numerical experiments to guide and manipulate the gap solitons to an arbitrary positionvia a time-dependent potential.All predictions of the extended variational approach are reasonably close to results ofthe simulations.In particular,the variational model helps capture the composition relationship between the variationsof chirp and amplitude.
文摘A high order finite difference scheme for solving the Regularised Long Wave(RLW) equation, based on the high order Pade approximation and Lax-Wendroff type timediscretization, was developed in this paper. Some numerical examples, including the propagation of asingle soliton, the interaction of double solitary waves and the temporal evolution of a Maxwellianinitial pulse, were studied to test the accuracy, efficiency and conservation property of thescheme. Compared with the results based on finite element methods, the scheme is proven successful.
