  Tunneling spectroscopy of one-dimensional interacting wires can be profoundly
sensitive to the boundary conditions of the wire. Here, we analyze the
tunneling spectroscopy of a wire coupled to capacitive metallic leads.
Strikingly, with increasing many-body interactions in the wire, the impact of
the boundary noise becomes more prominent. This interplay allows for a smooth
crossover from standard 1D tunneling signatures into a regime where the
tunneling is dominated by the fluctuations at the leads. This regime is
characterized by elevated zero-bias tunneling alongside a universal power-law
decay at high energies. Furthermore, local tunneling measurements in this
regime show a unique spatial-dependence that marks the formation of plasmonic
standing waves in the wire. Our result offers a tunable method by which to
control the boundary effects and measure the interaction strength (Luttinger
parameter) within the wire.
