Ac conductance and nonsymmetrized noise at finite frequency in quantum wires and carbon nanotubes

Abstract

We calculate the AC conductance and the finite-frequency non-symmetrized noise in interacting quantum wires and single-wall carbon nanotubes in the presence of an impurity. We observe a strong asymmetry in the frequency spectrum of the non-symmetrized excess noise, even in the presence of the metallic leads. We find that this asymmetry is proportional to the differential AC conductance of the system. The asymmetry disappears for a linear system (in the absence of interactions). In the quantum regime, for temperatures much smaller than the frequency and the applied voltage, we find that the emission noise is exactly equal to the impurity partition noise. Moreover the noise exhibits oscillations with respect to frequency, whose period is inversely proportional to the value of the interaction parameter g, and whose envelope is given by the noise in an infinite Luttinger liquid with the same value of g.