Non-equilibrium coherent thermal effects in quantum systems

Supervisor: Fabrizio Dolcini Co-supervisor: Davide Girolami

“Non-equilibrium coherent thermal effects in quantum systems” (NEThEQS) is a joint project between the “Nanophysics and Quantum Systems” group at Politecnico di Torino (Fabrizio Dolcini) and the CNR Institute of Nanoscience NANO-CNR in Pisa (Fabio Taddei), recently financed by the Italian Ministry of Research.

We aim to investigate the interplay between quantum coherent phenomena and non-equilibrium thermal effects. By suitably combining the complementary expertise of two units, the project addresses some specific open problems in the rapidly growing field of quantum thermodynamics, with a balance between fundamental questions of quantum thermal engines and some of their implementations.

At a more fundamental level, we shall consider a generic bipartite quantum system that converts a temperature gradient into work, acting as a heat engine. We shall investigate whether entanglement and other kinds of quantum correlations can improve the efficiency of a thermodynamic cycle. Then, we will extend the study to the multipartite case, by comparing the performance of machines in uncorrelated states and different kinds of multipartite quantum correlations.

At a more applicative level, we shall study specific implementations of thermal engines. Focussing on topological materials (e.g. quantum Hall or quantum Spin Hall systems), possibly coupled to superconductors, we shall investigate whether their phase-coherent transport can be exploited to control their thermoelectric response through electron quantum interference, to clarify the relation between entanglement of Cooper pairs and thermoelectric effects, and to compute the correlations of charge, heat and spin currents.   NEThEQS also aims to explore the heat dynamics in the far from equilibrium regime to understand how it is affected by the presence of topological states.

The PhD candidates are expected to combine analytical and numerical methods, and to actively cooperate across the two units. Fundings are also available for missions in Italy and to support other international collaborations (e.g. with Technische Universität Dresden) related to the project topics.