April 14, 2024
Mohammad Mohammadi

Mohammad Mohammadi

Academic Rank: Assistant professor
Address:
Degree: Ph.D in physic
Phone: 09171021581
Faculty: Faculty of Nano and Biotechnology

Research

Title Scattering of kinks in the Bφ^4 model
Type Article
Keywords
Soliton Kink scattering Resonance phenomena Topological defect Fractal
Journal CHAOS SOLITONS & FRACTALS
DOI 10.1016/j.chaos.2022.112805
Researchers Mohammad Mohammadi (First researcher) , Ehsan Momeni (Second researcher)

Abstract

In this study, based on the 𝜑4 model, a new model (called the 𝐵𝜑4 model) is introduced in which the potential form for the values of the field whose magnitudes are greater than 1 is multiplied by the positive number 𝐵. All features related to a single kink (antikink) solution remain unchanged and are independent of parameter 𝐵. However, when a kink interacts with an antikink in a collision, the results will significantly depend on parameter 𝐵. Hence, for kink–antikink collisions, many features such as the critical speed, output velocities for a fixed initial speed, two-bounce escape windows, extreme values, and fractal structure in terms of parameter 𝐵 are considered in detail numerically. The role of parameter 𝐵 in the emergence of a nearly soliton behavior in kink–antikink collisions at some initial speed intervals is clearly confirmed. The fractal structure in the diagrams of escape windows is seen for the regime 𝐵 ≤ 1. However, for the regime 𝐵 > 1, this behavior gradually becomes fuzzing and chaotic as it approaches 𝐵 = 3.3. The case 𝐵 = 3.3 is obtained again as the minimum of the critical speed curve as a function of 𝐵. For the regime 3.3 < 𝐵 ≤ 10, the chaotic behavior gradually decreases. However, a fractal structure is never observed. Nevertheless, it is shown that despite the fuzzing and shuffling of the escape windows, they follow the rules of the resonant energy exchange theory.