Tunneling-assisted acoustic-plasmon-quasiparticle excitation resonances incoupled quasi-one-dimensional electron gases

We show that a weak nonresonant tunneling between two quantum wires leads t o splitting of the acoustic plasmon mode at finite wave vector. Two gaps op en up in the dipersion of the acoustic plasmon mode when its frequency is c lose to the frequencies of the quasiparticle excitations. In contrast to th e Laudau damping of the collective excitations, these gaps are attributed t o tunneling-assisted acoustic plasmon-quasiparticle excitation resonances. We predict that such a resonance can be observed in inelastic light scatter ing spectrum.