Thermal transistor effect in quantum systems.

We study quantum systems of three interacting subsystems coupled to a different thermal reservoir each. We show how to engineer it in order to build a quantum thermal device in analogy to an electronic transistor. In particular, we address the ability to control the thermal currents at the emitter and collector imposing a non-varying thermal current at the base. Moreover, focusing on a system of three qubits, we outline how the interaction among them plays a crucial role for the appearance of the effect linking it also to the characteristics of system-bath interaction that governs the dissipation mechanism of the system.