  We analyze a bubble forming system composed of particles with competing long
range repulsive and short range attractive interactions driven over a
quasi-one-dimensional periodic substrate. We find various pinned and sliding
phases as a function of substrate strength and drive amplitude. When the
substrate is weak, a pinned bubble phase appears that depins elastically into a
sliding bubble lattice. For stronger substrates, we find anisotropic bubbles,
disordered bubbles, and stripe phases. Plastic depinning occurs via the hopping
of individual particles from one bubble to the next in a pinned bubble lattice,
and as the drive increases, there is a transition to a state where all of the
bubbles are moving but are continuously shedding and absorbing individual
particles. This is followed at high drives by a moving bubble lattice in which
the particles can no longer escape their individual bubbles. The transition
between the plastic and elastic sliding phases can be detected via signatures
in the velocity-force curves, differential conductivity, and noise. When the
bubbles shrink due to an increase in the attractive interaction term, they fit
better inside the pinning troughs and become more strongly pinned, leading to a
reentrant pinning phase. For weaker attractive terms, the size of the bubbles
becomes greater than the width of the pinning troughs and the depinning becomes
elastic with a reduced depinning threshold.
