Solitary and double-layer structures in quantum bi-ion plasma

Weak ion-acoustic solitary waves (IASWs) inan unmagnetized quantum plasmas having two-fluid ionsand fluid electrons are considered. Using the one-dimensionalquantum hydrodynamics model and then thereductive perturbation technique, a generalized form ofnonlinear quantum Korteweg-de Vries (KdV) equationgoverning the dynamics of weak ion acoustic solitarywaves is derived. The effects of ion population, warm iontemperature, quantum diffraction, and polarity of ions onthe nonlinear properties of these IASWs are analyzed. It isfound that our present plasma model may support compressiveas well as rarefactive solitary structures. Furthermore,formation and characteristics properties of IA doublelayers in the present bi-ion plasma model are investigated.The results of this work should be useful and applicable inunderstanding the wide relevance of nonlinear features oflocalized electro-acoustic structures in laboratory andspace plasma, such as in super-dense astrophysical objects[24] and in the Earth’s magnetotail region (Parks [43]. Theimplications of our results in some space plasma situationsare discussed.