  The charge transport of a (Tomonaga-)Luttinger liquid with tunnel barriers
exhibits universal scaling: the current-voltage curves measured at various
temperatures collapse into a single curve upon rescaling. The exponent
characterizing this single curve can be used to extract the strength of
electron-electron interaction. Motivated by a recent experiment on InAs
nanowires [Sato et al., Phys. Rev. B 99, 155304 (2019)], we theoretically
investigate the analogous behavior of a spin-orbit-coupled Luttinger liquid. We
find that the scaling exponent differs for different impurity strengths, being
weak (disorder potential) or strong (tunnel barriers), and their positions,
either in the bulk or near the edge of the wire. For each case we quantify the
exponent of the universal scaling and its modification due to the spin-orbit
coupling. Our findings serve as a guide in the determination of the interaction
strength of quasi-one-dimensional spin-orbit-coupled quantum wires from
transport measurements.
