A single-quantum-dot heat valve

A Scanning electron microscope (SEM) image of the researchers’ experimental setup. Credit: Dutta et al.

A team of researchers at University Grenoble Alpes and Centre of Excellence Quantum Technology has developed a single-quantum-dot heat valve. They have demonstrated gate control of electronic heat flow in a thermally biased single-quantum-dot junction.

One of the key objectives was to demonstrate the feasibility of controlling the amount of heat that flows across a quantum dot junction, while also enabling the flow of a set amount of electric current. To design their single-quantum-dot heat valve, the researchers placed a gold nanoparticle between two metallic contacts, using it as a junction. This nanoparticle is so small that it can be used to intervene on a single energy level, acting as a bigger artificial atom would with several accessible energy levels.

Electron temperature maps taken in the immediate vicinity of the junction, as a function of the gate and bias voltages applied to the device, reveal clearly defined Coulomb diamond patterns that indicate a maximum heat transfer at the charge degeneracy point. The nontrivial bias and gate dependence of this heat valve results from the quantum nature of the dot at the heart of device and its strong coupling to leads.

In the future, the heat valve developed by this team of researchers could improve the reliability and safety of quantum devices, reducing the risk of overheating. (Phys.org)

The paper has been published in Physical Review Letters.

Read more.