Violation of the Wiedemann-Franz Law in a Single-Electron Transistor
Bj\"orn Kubala, J\"urgen K\"onig, J. P. Pekola
TL;DR
This paper investigates how Coulomb interactions in a single-electron transistor cause significant deviations from the Wiedemann-Franz law, revealing gate-dependent Lorenz ratios and proposing an experimental measurement approach.
Contribution
It provides a detailed perturbative analysis of Coulomb effects on thermoelectric transport, highlighting a strong violation of the Wiedemann-Franz law in such systems.
Findings
Lorenz ratio becomes gate-voltage dependent in sequential tunneling
Lorenz ratio increases by 9/5 in cotunneling regime
Proposes an experimental measurement scheme
Abstract
We study the influence of Coulomb interaction on the thermoelectric transport coefficients for a metallic single-electron transistor. By performing a perturbation expansion up to second order in the tunnel-barrier conductance, we include sequential and cotunneling processes as well as quantum fluctuations that renormalize the charging energy and the tunnel conductance. We find that Coulomb interaction leads to a strong violation of the Wiedemann-Franz law: the Lorenz ratio becomes gate-voltage dependent for sequential tunneling, and is increased by a factor 9/5 in the cotunneling regime. Finally, we suggest a measurement scheme for an experimental realization.
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.