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arXiv · 0709.4181

Violation of the Wiedemann-Franz Law in a Single-Electron Transistor

Björn Kubala·Jürgen König·J. P. Pekola
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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.

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Björn Kubala, Jürgen König, J. P. Pekola. 2008-04-04. Violation of the Wiedemann-Franz Law in a Single-Electron Transistor. https://doi.org/10.1103/physrevlett.100.066801

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