Celestino Creatore

In Plain English

Heat engines convert heat (thermal energy) into mechanical energy, which is used to perform mechanical work. In the simplest configuration, this is achieved using a couple of thermal reservoirs, an hot and a cold sources, in contact with a working substance (e.g. a gas or a liquid). Heat engines have been intensively studied since the beginning of the industrial revolution, with the aim to enhance their efficiency, i.e their ability to perform work. Recently, an increasing attention has been devoted to understand the working principles of heat engines whose working substance is a quantum system, i.e a system characterised by quantised/discrete energy levels, consisting e.g. of artificial atoms or quantum dots. The realisation of a QHE was first conceived in the 1960s by Scovil and Dubois, who showed the equivalence between the classical Carnot engine and a three-level quantum system (a maser) coupled to two thermal sources. However, it took more than fifty years to recognise that QHEs could exhibit new and intriguing thermodynamic effects with potential applications ranging from quantum optics to solar energy harvesting.

My research activity is focused on developing novel schemes of quantum heat engines. In particular, I am working on thermodynamic implementations that can be used to design a new class of solar energy harvesting devices (e.g. solar cells) driven by quantum effects. Indeed, a photocell can be described in terms of a thermodynamic heat engine in which a "hot" thermal bath represented by the solar energy is (partially) converted into useful work through the production of high energy electrons used for current/power generation. A fascinating direction I am currently exploring draws on the utility of the QHE framework and is inspired by the nanoscale architecture of biological photosynthetic complexes, which, under certain conditions, behave as highly efficient heat engines.