Physics – Condensed Matter – Strongly Correlated Electrons
Scientific paper
2010-01-21
Phys. Rev. B 81, 165115 (2010)
Physics
Condensed Matter
Strongly Correlated Electrons
23 pages, 10 figures
Scientific paper
10.1103/PhysRevB.81.165115
The paper deals with the nonequilibrium two-lead Anderson model, considered as an adequate description for transport through a d-c biased quantum dot. Using a self-consistent equation-of-motion method generalized out of equilibrium, we calculate a fourth-order decoherence rate $\gamma^{(4)}$ induced by a bias voltage $V$. This decoherence rate provides a cut-off to the infrared divergences of the self-energy showing up in the Kondo regime. At low temperature, the Kondo peak in the density of states is split into two peaks pinned at the chemical potential of the two leads. The height of these peaks is controlled by $\gamma^{(4)}$. The voltage dependence of the differential conductance exhibits a zero-bias peak followed by a broad Coulomb peak at large $V$, reflecting charge fluctuations inside the dot. The low-bias differential conductance is found to be a universal function of the normalized bias voltage $V/T_K$, where $T_K$ is the Kondo temperature. The universal scaling with a single energy scale $T_K$ at low bias voltages is also observed for the renormalized decoherence rate $\gamma^{(4)}/T_K$. We discuss the effect of $\gamma^{(4)}$ on the crossover from strong to weak coupling regime when either the temperature or the bias voltage is increased.
Lavagna Mireille
Roermund Raphaël Van
Shiau Shiue-Yuan
No associations
LandOfFree
Anderson Model out of equilibrium: decoherence effects in transport through a quantum dot does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Anderson Model out of equilibrium: decoherence effects in transport through a quantum dot, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Anderson Model out of equilibrium: decoherence effects in transport through a quantum dot will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-654900