  Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) inhomogeneous superconducting (SC)
state, first- and second-order phase transitions, and quantum criticality
induced by spin accumulation in a ferromagnet-$d_{x^{2}-y^{2}}$-wave
superconductor-ferromagnet tunnel junction are theoretically predicted. A
complex phase diagram in the temperature-bias voltage plane is determined. It
is found that the phase transitions from the homogeneous BCS state to the
inhomogeneous FFLO state, and from the FFLO state with the momentum $\mathbf{%
q}$'s azimuthal angle $\theta_{\mathbf{q}}=0$ to that with $\theta_{%
\mathbf{q}}=\pi /4$, are of the first-order; while the transitions from all SC
states to the normal state at critical voltages are of the second-order. A
Lifshitz point, a bicritical point and a quantum critical point are identified.
