ELECTRONIC INSTABILITY IN DOUBLE-QUANTUM-WIRE STRUCTURES

We discuss a charge-density-wave instability for electrons in quasi-one-dimensional structures due to Coulomb interaction effects. The two plasmon modes (omega+,omega-) of a double-quantum-wire structure are studied. The effect of a finite local-field correction is discussed. For small wavenumbers, it is shown that for a fixed wire distance and wire radius the energy of the omega- plasmon vanishes if the particle density is smaller than a critical value. The disappearance of the omega- mode corresponds to a singularity in the static susceptibility of the system.