Strong electron-electron interactions of a Tomonaga-Luttinger liquid observed in InAs quantum wires

We report strong electron-electron interactions in quantum wires etched from an InAs quantum well, a material generally expected to have strong spin-orbit interactions. We find that the current through the wires as a function of the bias voltage and temperature follows the universal scaling behavior of a Tomonaga-Luttinger liquid. Using a universal scaling formula, we extract the interaction parameter and find strong electron-electron interactions, increasing as the wires become more depleted. We establish theoretically that the spin-orbit interaction cause only minor modifications of the interaction parameter in this regime, indicating that genuinely strong electron-electron interactions are indeed achieved in the device. Our results suggest that etched InAs wires provide a platform with both strong electron-electron interactions and the strong spin-orbit interaction.