Magnetic Fields and Solitons in Relativistic Plasmas

In this paper we show that relativistic nonlinearities in a plasma interacting with ultra short high intensity laser pulses, lead to the formation of long-lived, slowpropagating coherent structures such as magnetic vortices and solitons. These structures are part of the complex nonlinear interaction between the laser pulse and the underdense plasma and represent the basic ingredients of the long time electron behaviour in the wake of the laser pulse.