A new direction in the study of MHD-scale non-linear Kelvin-Helmholtz vortices

For understanding the structure of an MHD-scale Kelvin-Helmholtz Instability (KHI) in a non-linear stage, we have performed two-dimensional two-fluid simulations including finite electron inertial effects. In the twofluid system, magnetic reconnection occurs spontaneously because the ’frozen-in’ condition can be broken by the electron inertial effects. When an MHD-scale velocity shear exists, a current sheet that is too thick for magnetic reconnection can become a thin current sheet by the MHD-scale KH vortex flow and then magnetic reconnection occurs within the vortex flow by the electron effects. Moreover, magnetic reconnection affects largely the structure of the MHD-scale KH vortex itself.