  We compute one-loop effective action of magnetic monopole in
three-dimensional electrodynamics of massless bosons and fermions and find that
it contains an infrared logarithm. So, when the number of massless matter
species is sufficiently large, monopoles are suppressed and in the weak
coupling limit charged particles are unconfined. This result provides some
support to gauge theories of high-temperature superconductors. It also provides
a mechanism by which interlayer tunneling of excitations with one unit of the
ordinary electric charge can be suppressed while that of a doubly charged
object is allowed.
