Vortex Solitons in Poly-Acetylene

Tapas Kumar Sinha, Sanjib Malla Bujar Baruah, Joseph Mathew

Abstract: Solitons in Poly-Acetylene have been both predicted theoretically and found experimentally. However as is shown in this paper Vortex Soliton solutions are also possible. One feature of the Vortex solutions is that a small change in the parameters (bond angles) induces a large change in the interaction potential. This induces extended discontinuities in the wave vector space of the system. A large block of states are even absent due to the presence of vortices. A depleted number of states is thus forced to accommodate the original number of spins and charges in the system. The only way this is possible that two spins pair up to form a spin less charged Vortex. As a result vortices may be with spin or without spin and also with or without charge. This phenomenon is confirmed via numerical simulations on Poly-Acetylene.

Keywords: Poly-Acetylene, Nonlinear optical lattice, vortex Solitons, Sine-Gordon Equation, DNLS