  A one-dimensional, two-channel quantum wire is studied in the effective
non-Hermitian Hamiltonian framework. Analytical expressions are derived for the
band structure of the isolated wire. Quantum states and transport properties of
the wire coupled to two ideal leads at the edges are studied in detail. The
width distribution of the quasistationary states varies as a function of the
coupling strength to the environment. At weak coupling, all the eigenenergies
uniformly acquire small widths. The picture changes entirely at strong
coupling, a certain number of states ("super-radiant") are greatly broadened,
while the rest remain long-lived states, a pure quantum mechanical effect as a
consequence of quantum interference. The transition between the two regimes
greatly influences the transport properties of the system. The maximum
transmission through the wire occurs at the super-radiance transition. We
consider also a realistic situation with energy-dependent coupling to the
continuum due to the existence of decay threshold where super-radiance still
plays a significant role in transport properties of the system.
