  In this paper we study the time evolution of (Renyi) entanglement entropies
for locally excited states in four dimensional free massless fermionic field
theory. Locally excited states are defined by being acted by various local
operators on the ground state. Their excesses are defined by subtracting
(Renyi) entanglement entropy for the ground state from those for locally
excited states. They finally approach some constant if the subsystem is given
by half of the total space. They have spin dependence. They can be interpreted
in terms of quasi-particles.
