National Natural Science Foundation of China [21103001]; Research Fund for the Doctoral Program of Higher Education of China [20113401120004]We investigated the ground and excited state electronic properties of finite length zigzag graphene nanoribbons, using time-dependent density functional theory. The ground state of short graphene nanoribbons with eight Hatoms on their armchair edges (8-ZGNR) is diamagnetic, and antiferromagnetismcan be exhibited with increasing the length of nanoribbons. The antiferromagnetismand half-metallicity can also be shown when a static field is added. When a laser pulse is applied in the excited state, the induced electrons can move and change with the laser pulse. There exist some differences between alpha- and beta-spin electrons. alpha-Spin electrons can be induced, and show induced charge density more readily. beta-Spin electrons can escape the external field control, and show non-adiabatic properties more readily
