Universal scaling in nonequilibrium transport through an Anderson impurity

Using nonequilibrium renormalized perturbation theory, we calculate the conductance $G$ as a function of temperature $T$ and bias voltage $V$ for an Anderson model suitable for describing transport properties through a quantum dot. For renormalized parameters that correspond to the extreme Kondo limit, we do not find a simple scaling formula beyond a quadratic dependence in $T$ and $V$. However, if valence fluctuations are allowed, we find excellent agreement with recent experiments.

Figure 1

Conductance shift for $V=0$ as a function of temperature for $\tilde{u}=1$. Dashed line corresponds to the EMP curve [Eq. (3)].

Figure 2

(Color online) Scaled conductance shift as a function of bias voltage for different temperatures and $\tilde{u}=1$.

Figure 3

Conductance shift for $V=0$ as a function of temperature for $\tilde{u}=0.365$. Dashed line corresponds to Eq. (3).

Figure 4

(Color online) Scaled conductance shift as a function of bias voltage for different temperatures and $\tilde{u}=0.365$.