Appearance of Fractional Charge in the Noise of Nonchiral Luttinger Liquids

Björn Trauzettel, Inès Safi, Fabrizio Dolcini, Hermann Grabert
2004 Physical Review Letters  
The current noise of a voltage biased interacting quantum wire adiabatically connected to metallic leads is computed in presence of an impurity in the wire. We find that in the weak backscattering limit the Fano factor characterizing the ratio between noise and backscattered current crucially depends on the noise frequency ω relative to the ballistic frequency v_F/gL, where v_F is the Fermi velocity, g the Luttinger liquid interaction parameter, and L the length of the wire. In contrast to
more » ... In contrast to chiral Luttinger liquids the noise is not only due to the Poissonian backscattering of fractionally charged quasiparticles at the impurity, but also depends on Andreev-type reflections at the contacts, so that the frequency dependence of the noise needs to be analyzed to extract the fractional charge e^*=e g of the bulk excitations.
doi:10.1103/physrevlett.92.226405 pmid:15245245 fatcat:rntuqc3g5rcnlogky76yh2m4lq