Nonlinear conductance of nanowires - A signature of Luttinger liquid effects?

We analyze recent measurements of the room temperature current-voltage characteristics of gold nanowires, whose zero current conductance is quantized in units of $2e^2/h$. A faster than linear increase of current with voltage was observed at low voltages beginning from $V_c=0.1$V. We analyze the nonlinear behavior in terms of a dynamic Coulomb blockade of conducting modes and show that it may be explained as a Luttinger-liquid effect.Comment: 13 pages, latex with supplied stylefile, 3 figures in eps format, submitted to Superlattices and Microstructure

Gauge Fields Condensation at Finite Temperature

The two-loop effective action for the SU(3) gauge model in a constant background field ${\bar A}_0(x,t)=B_0^3T_3+B_0^8T_8$ is recalculated for a gauge with an arbitrary $\xi$-parameter. The gauge-invariant thermodynamical potential is found and its extremum points are investigated. Within a two-loop order we find that the stable nontrivial vacuum is completely equivalent to the trivial one but when the high order corrections being taken into account the indifferent equilibrium seems to be broken. Briefly we also discuss the infrared peculiarities and their status for the gauge models with a nonzero condensate.Comment: 6pages, LATEX, Preprint FIAN/TD/06-92(May 1992

Influence of the Rashba effect on the Josephson current through a superconductor/Luttinger liquid/superconductor tunnel junction

The Josephson current through a 1D quantum wire with Rashba spin-orbit and electron-electron interactions is calculated. We show that the interplay of Rashba and Zeeman interactions gives rise to a supercurrent through the 1D conductor that is anomalous in the sense that it persists in the absence of any phase difference between the two superconducting leads to which it is attached. The electron dispersion asymmetry induced by the Rashba interaction in a Luttinger-liquid wire plays a significant role for poorly transmitting junctions. It is shown that for a weak or moderate electron-electron interaction the spectrum of plasmonic modes confined to the normal part of the junction becomes quasi-random in the presence of dispersion asymmetry.Comment: 25 pages, 3 figure

Persistent current in a one-dimensional ring of fractionally charged "exclusons''

The Aharonov-Bohm effect in a one-dimensional (1D) ring containing a gas of fractionally charged excitations is considered. It is shown that the low temperature behavior of the system is identical to that of free electrons with (integer) charge $e$. This is a direct consequence of the fact that the total charge in the ring is quantized in units of the electron charge. Anomalous oscillations of the persistent current amplitude with temperature are predicted to occur as a direct manifistation of the fractional nature of the quasiparticle charge. A 1D conducting ring with gate induced periodical potential is discussed as a possible set-up for an experimental observation of the predicted phenomenon.Comment: 4 pages, RevTex, uuencoded figure