# Non-Linear Thermovoltage in a Single-Electron Transistor

## TL;DR

This study measures thermovoltage in a single-electron transistor, demonstrating the impact of co-tunneling and island overheating in non-linear regimes, with a validated model matching experimental data without free parameters.

## Contribution

It introduces a comprehensive model including co-tunneling effects that accurately predicts thermovoltage behavior in non-linear regimes without free parameters.

## Key findings

- Thermovoltage is highly sensitive to co-tunneling effects.
- The metallic island overheats even at zero net charge current.
- The model matches experimental data across linear and non-linear regimes.

## Abstract

We perform direct thermovoltage measurements in a single-electron transistor, using on-chip local thermometers, both in the linear and non-linear regimes. Using a model which accounts for co-tunneling, we find excellent agreement with the experimental data with no free parameters even when the temperature difference is larger than the average temperature (far-from-linear regime). This allows us to confirm the sensitivity of the thermovoltage on co-tunneling and to find that in the non-linear regime the temperature of the metallic island is a crucial parameter. Surprisingly, the metallic island tends to overheat even at zero net charge current, resulting in a reduction of the thermovoltage.