Super 0-brane and GS Superstring Actions on AdS_2 \times S^2

The super 0-brane and GS superstring actions on AdS$_2 \times S^2$ background with 2-form flux are constructed by supercoset approach. We find the super 0-brane action contains two parameters which are interpreted as the electric and magnetic charges of the super 0-brane. The obtained super 0-brane action describes the BPS saturated dyonic superparticle moving on AdS$_2 \times S^2$ background. The WZ action contains the required coupling with 2-form flux. For GS superstring, we find the string action on AdS$_2 \times S^2$ takes the same form as those in AdS$_3 \times S^3$ and AdS$_5 \times S^5$ with RR field background.