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P. Queipo

Publications and source records attributed to P. Queipo.

2 recordsLinked to original sources

Single-walled carbon nanotube weak links: from Fabry-Pérot to Kondo regime

We have investigated proximity-induced supercurrents in single-walled carbon nanotubes in the Kondo regime and compared them with supercurrents obtained on the same tube with Fabry-Pérot resonances. Our data display a wide distribution of Kondo temperatures \emph{$T_K$} = 1 - 14 K, and the measured critical current $I_{CM}$ vs. \emph{$T_K$} displays two distinct branches; these branches, distinguished by zero-bias splitting of the normal-state Kondo conductance peak, differ by an order of magnitude at large values of $T_K$. Evidence for renormalization of Andreev levels in Kondo regime is also found.

cond-mat.supr-con

Shot Noise with Interaction Effects in Single Walled Carbon Nanotubes

We have measured shot noise in single walled carbon nanotubes (SWNT) with good contacts at 4.2 K at low frequencies ($f=600 - 850$ MHz). We find a strong modulation of shot noise over the Fabry-Perot pattern; in terms of differential Fano factor the variation ranges over 0.4 - 1.2. The shot noise variation, in combination with differential conductance, is analyzed using two (spin-degenerate) modes with different, energy-dependent transmission coefficients. No power law dependence of shot noise, as expected for Luttinger liquids, was found in our measurements.

cond-mat.mes-hall