Hybrid metal-semiconductor devices based on metallic islands embedded in a two-dimensional electron gas provide a versatile platform for exploring quantum transport phenomena. These systems enable studies of dynamical Coulomb blockade, electron teleportation, and non-Fermi-liquid behavior in multi-channel and multi-impurity charge Kondo models. One of the most striking recent discoveries in this context is the heat Coulomb blockade [1, 2], in which the heat flow through N ballistic channels is universally suppressed by a single quantum of thermal conductance. In this seminar, I will discuss a double-island metal-semiconductor circuit – a device recently realized experimentally [3] to explore frustrated interactions at an exotic quantum critical point. The presence of two interacting charge modes leads to a more subtle suppression of heat transport compared to the single-island configuration. I will also show how the geometry of the conducting channels controls both the thermal current and the inter-island equilibration, providing a tunable route to violating the Wiedemann–Franz law. The Lorenz number, as a benchmark of non-Fermi-liquid properties, will also be discussed.

 

[1] E. Sivre et al., Nature Physics 14, 145 (2018).

[2] A. Slobodeniuk et al., Phys. Rev. B 88, 165307 (2013).

[3] W. Pouse et al., Nature Physics 19, 492 (2023).