We calculate the width $2{\mathrm{\ensuremath{\Delta}}}_{\text{CT}}$ and intensity of the charge-transfer peak (the one lying at the on-site energy ${E}_{d}$ ) in the impurity spectral density of states as a function of ${E}_{d}$ in the SU( $N$ ) impurity Anderson model (IAM). We use the dynamical density-matrix renormalization group (DDMRG) and the noncrossing approximation (NCA) for $N=4$ and a 1/ $N$ variational approximation in the general case. In particular, while for ${E}_{d}\ensuremath{\gg}\mathrm{\ensuremath{\Delta}}$, where $\mathrm{\ensuremath{\Delta}}$ is the resonant level half-width, ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}=\mathrm{\ensuremath{\Delta}}$ as expected in the noninteracting case, for $\ensuremath{-}{E}_{d}\ensuremath{\gg}N\mathrm{\ensuremath{\Delta}}$ one has ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}=N\mathrm{\ensuremath{\Delta}}$. In the $N=2$ case, some effects of the variation of ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}$ with ${E}_{d}$ were observed in the conductance through a quantum dot connected asymmetrically to conducting leads at finite bias [J. K\"onemann et al., Phys. Rev. B 73, 033313 (2006)]. More dramatic effects are expected in similar experiments that can be carried out in systems of two quantum dots, carbon nanotubes or other, realizing the SU(4) IAM.We calculate the width $2{\mathrm{\ensuremath{\Delta}}}_{\text{CT}}$ and intensity of the charge-transfer peak (the one lying at the on-site energy ${E}_{d}$) in the impurity spectral density of states as a function of ${E}_{d}$ in the SU($N$) impurity Anderson model (IAM). We use the dynamical density-matrix renormalization group (DDMRG) and the noncrossing approximation (NCA) for $N=4$ and a 1/$N$ variational approximation in the general case. In particular, while for ${E}_{d}\ensuremath{\gg}\mathrm{\ensuremath{\Delta}}$, where $\mathrm{\ensuremath{\Delta}}$ is the resonant level half-width, ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}=\mathrm{\ensuremath{\Delta}}$ as expected in the noninteracting case, for $\ensuremath{-}{E}_{d}\ensuremath{\gg}N\mathrm{\ensuremath{\Delta}}$ one has ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}=N\mathrm{\ensuremath{\Delta}}$. In the $N=2$ case, some effects of the variation of ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}$ with ${E}_{d}$ were observed in the conductance through a quantum dot connected asymmetrically to conducting leads at finite bias [J. K\"onemann et al., Phys. Rev. B 73, 033313 (2006)]. More dramatic effects are expected in similar experiments that can be carried out in systems of two quantum dots, carbon nanotubes or other, realizing the SU(4) IAM.

arXiv:1711.10835Physical review. B./Physical review. BJan 25, 201810 citations

Quantumness of Electron Transport in Quantum Dots: Nonequilibrium Green's Function Approach

Md. Manirul Ali, Thingujam Yaiphalemba Meitei, Saikumar Krithivasan +1 more

Jan 1, 20240 citations

Two-impurity Anderson model at quantum criticality

David F. Mross, Henrik Johannesson

We propose a realization of the two-impurity Anderson model in a double quantum-dot device. When charge transfer between the dots is suppressed, the system exhibits a quantum phase transition, which is controlled by a surface of non-Fermi-liquid fixed points parameterized by the charge valences of the dots. Employing conformal field theory techniques, we identify the scaling exponents that govern transport and thermodynamics close to criticality. We also determine the dynamical exponents that set the time scale for the buildup of the non-Fermi-liquid state after the system is suddenly shifted into the critical region, e.g., by a change of a nearby gate voltage.We propose a realization of the two-impurity Anderson model in a double quantum-dot device. When charge transfer between the dots is suppressed, the system exhibits a quantum phase transition, which is controlled by a surface of non-Fermi-liquid fixed points parameterized by the charge valences of the dots. Employing conformal field theory techniques, we identify the scaling exponents that govern transport and thermodynamics close to criticality. We also determine the dynamical exponents that set the time scale for the buildup of the non-Fermi-liquid state after the system is suddenly shifted into the critical region, e.g., by a change of a nearby gate voltage.

arXiv:0712.2868Physical Review BJul 31, 20085 citations

Nonequilibrium steady-state transport in quantum impurity models

Frauke Schwarz

Jan 1, 20170 citations

We calculate the width $2{\mathrm{\ensuremath{\Delta}}}_{\text{CT}}$ and intensity of the charge-transfer peak (the one lying at the on-site energy

{E}_{d}

) in the impurity spectral density of states as a function of

{E}_{d}

in the SU(

N

) impurity Anderson model (IAM). We use the dynamical density-matrix renormalization group (DDMRG) and the noncrossing approximation (NCA) for

N=4

and a 1/

N

variational approximation in the general case. In particular, while for ${E}_{d}\ensuremath{\gg}\mathrm{\ensuremath{\Delta}}$, where $\mathrm{\ensuremath{\Delta}}$ is the resonant level half-width, ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}=\mathrm{\ensuremath{\Delta}}$ as expected in the noninteracting case, for $\ensuremath{-}{E}_{d}\ensuremath{\gg}N\mathrm{\ensuremath{\Delta}}$ one has ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}=N\mathrm{\ensuremath{\Delta}}$. In the

N=2

case, some effects of the variation of ${\mathrm{\ensuremath{\Delta}}}_{\text{CT}}$ with

{E}_{d}

were observed in the conductance through a quantum dot connected asymmetrically to conducting leads at finite bias [J. K\"onemann et al., Phys. Rev. B 73, 033313 (2006)]. More dramatic effects are expected in similar experiments that can be carried out in systems of two quantum dots, carbon nanotubes or other, realizing the SU(4) IAM.