Inhomogeneity-induced multi-solitons in gyrotropic molecular chains

This paper investigates the dynamics of inhomogeneous gyrotropic molecular chains by proposing a suitable Hamiltonian model. The modulational instability phenomenon is explored in gyrotropic media of α−helical protein chains under controllable inhomogeneities, arising from the constitution of the molecular chains, which can be sequence-dependent or influenced by gyrotropic dipole–dipole interactions due to the presence of additional molecules, such as drugs, at specific sites in the amino acid sequence. The linear stability analysis of continuous wave solutions is conducted on the inhomogeneous gyrotropic coupled nonlinear Schrödinger equations. We observe that both gyrotropy and inhomogeneity can increase or decrease the number of sidelobes in the instability spectrum. We construct new variational solitary wave solutions in the presence of inhomogeneities, revealing that energy transport can be more accurately described by the generation of pulses, bright solitons, and multisolitons involving rotational movement induced by the increasing gyrotropic parameters.