  We demonstrate a novel way to form and deplete a vapor-cell magneto-optic
trap (MOT) using a reversible, solid-state alkali-metal source (AMS) via an
applied polarized voltage. Using ~100 mW of electrical power, a trapped-atom
number of 5x10^6 has been achieved starting from near zero and the timescales
of the MOT formation and depletion of ~1 s. This fast, reversible, and low
power alkali-atom source is desirable in both tabletop and portable cold-atom
systems. The core technology of this device should translate readily to other
alkali and alkaline-earth elements that could find a wide range of uses in
cold-atom systems and instruments.
