Electromagnetic electron Kelvin–Helmholtz instability

On electron kinetic scales, ions and electrons decouple, velocity shear on inertial length ∼de can trigger electromagnetic (EM) Kelvin–Helmholtz instability (EKHI). In this paper, we present an analytic study of EM EKHI in inviscid collisionless plasma with a step-function flow. We show that incompressible plasma, the ideal frozen-in condition E+ve×B/c=0 must be broken for to occur. flow, is replaced by magnetic flux conservation, i.e., ∇×(E+ve×B/c)=0, resulting dispersion relation similar standard magnetohydrodynamics KHI. The field parallel streaming suppresses due tension. threshold mode (k·ΔUe)2>ne1+ne2ne1ne2[ne1(vAe1·k)2+ne2(vAe2·k)2], where vAe=B/(4πmene)1/2, ΔUe, ne are densities, respectively. growth rate γem∼Ωce, which gyro-frequency.