Temperature dependence of Fano line shapes in a weakly coupled single-electron transistor - art. no. 155311

We report the temperature dependence of the zero-bias conductance of a sing le-electron transistor in the regime of weak coupling between the quantum d ot and the leads. The Fano line shape, convoluted with thermal broadening, provides a good fit to the observed asymmetric Coulomb charging peaks. Howe ver, the width of the peaks increases more rapidly than expected from the t hermal broadening of the Fermi distribution in a temperature range for whic h Fano interference is unaffected. The intrinsic width of the resonance ext racted from the fits increases approximately quadratically with temperature . Above about 600 mK the asymmetry of the peaks decreases, suggesting that phase coherence necessary for Fano interference is reduced.