Bath-induced band-decay in a spin-dependent optical lattice

We have measured the bath-induced band-decay rate for a thermal gas of $^{87}$Rb atoms trapped in a cubic, fully spin-dependent optical lattice. Atoms in the $\left|F=1,m_F=-1\right\rangle$ state are confined in the lattice and driven to the first-excited band via stimulated Raman transitions. We compare rates for decay to the ground band in the presence and absence of a bath consisting of a $\left|F=1,m_F=0\right\rangle$ BEC that does not experience the lattice potential. For lattice depths in the Mott-insulator regime, we measure increased decay rates induced by the bath atoms. This talk will include a discussion of decay mechanisms, and the importance of bath-induced decay to proposed methods for cooling quasimomentum distributions in a lattice.