  We study a hybrid structure of a ferromagnetic-insulator and a superconductor
connected by a weak link, which accommodates Andreev bound states whose spin
degeneracy is lifted due to the exchange interaction with the ferromagnet. The
resultant spin-resolved energy levels realize a two-state quantum system,
provided that a single electron is trapped in the bound state, i.e., an Andreev
spin qubit. The qubit state can be manipulated by controlling the magnetization
dynamics of the ferromagnet, which mediates the coupling between external
fields and the qubit. In particular, our hybrid structure provides a simple
platform to manipulate and control the spin qubit using spintronic techniques.
By employing a modified Hahn spin echo protocol for the magnetization dynamics,
we show that our Andreev spin qubit can realize a nonadiabatic geometric gate.
