Early Stage Researcher 3, CNRS, FRANCE


Project title and work package:

Theory of heat transfer in nanostructures: microscopic and phenomenological approaches, work package Quantum thermodynamics



You will carry out a detailed theoretical analysis of the heat transfer between various parts of a nanodevice. The mechanisms that dominate at low temperature are (i) particle transfer between metallic parts in direct contact and (ii) transfer by photons, a channel that also works for metallic parts that are connected only capacitively.

For particle transfer, you will focus on structures combining both normal metals and superconductors which are relevant for experimental projects of Early Stage Researchers 1 (CNRS, France), 2 (CNRS, France), 5 (AALTO, Finland) and 6 (UKON, Germany). In this case, heat transfer is due to the interplay between single particle transfer and coherent multi-particle transfer (elastic co-tunnelling and Andreev reflection), which can have a strong effect on device performance.

Photon heat transfer is often described using circuit theory. The limits of applicability of this powerful tool however, are not well known. In collaboration with Early Stage Researcher 7 (UKON, Germany) you will investigate the way thin films and nanowires exchange heat through photon exchange, using a microscopic approach and establish under which conditions the predictions of circuit theory, such as the quantisation of thermal conductance, are valid. You will also study the photon heat transfer between a driven quantum dot or a qubit and its dissipative environment using the quantum jump method in regimes of strong drive or coupling where fundamental questions related to heat, internal energy and work for a given trajectory need special attention>


Expected Results:

- Link between the circuit approach and the microscopic theory of photon heat transfer.

- Full counting statistics of photon heat transfer with quantum jump approach in a strongly driven quantum dot or qubit system.

- Proposal for specific measurement protocols enabling to collect the relevant statistics in experiments.


Planned secondments:

at AALTO, Finland (1 month Year 1, 1 month Year 3) to learn experimental specificities, at UKON, Germany (2 months Year 1, 1 month Year 2, 1 month Year 3) to learn non-equilibrium Green’s function techniques, at EDP Sciences, France (2 months, Year 2), to get trained in challenges in scientific publishing.