Abstract
As a model of thermally excited flux liquids connected by a weak link, we study the effect
of a single line defect on vortex filaments oriented parallel to the surface of a thin planar
superconductor. This problem can be mapped onto the physics of a Luttinger liquid of
interacting bosons in one spatial dimension with a point impurity. When the applied
magnetic field is tilted relative to the line defect, the corresponding quantum boson
Hamiltonian is non-Hermitian. We analyse this problem using a combination of analytic
and numerical (density matrix renormalization group) methods, uncovering a delicate
interplay between enhancement of pinning due to Luttinger liquid effects and depinning
due to the tilted magnetic field. Interactions allow a single columnar defect to be very
effective in suppressing vortex tilt when the Luttinger liquid parameter 
.