Spin and charge Tomonaga-Luttinger parameters in quantum wires

Low-energy properties of the homogeneous electron gas in one dimension are completely described by the group velocities of its charge (plasmon) and sp in collective excitations. Because of the long range of the electron-electr on interaction, the plasmon velocity is dominated by an electrostatic contr ibution and can be estimated accurately. We report on Quantum Monte Carlo s imulations which demonstrate that the spin velocity is substantially decrea sed by interactions in semiconductor quantum wire realizations of the one-d imensional electron liquid.