Nanophysics

Group “Statistical Physics and Condensed Matter”

The nanophysics team at the CPT studies electronic transport in nanoscale and mesoscopic systems in condensed matter. The small size of these systems, and the conditions under which they are studied (low temperature, dimensionality, …), make it possible to preserve quantum coherence and to obtain novel behaviors arising from the fundamental properties of quantum mechanics.

A first research direction concerns superconducting and hybrid devices. In a superconductor, electrons are paired into Cooper pairs, and the coherent transport of pairs between two superconductors leads to the Josephson current. We have studied the properties of the Josephson current when it flows through a magnetic molecule, a semiconductor with spin–orbit coupling, etc. We also study out-of-equilibrium multi-terminal superconducting and hybrid devices, which make it possible to spatially separate the two electrons of Cooper pairs, thereby generating quantum entanglement.

A second research direction concerns the quantum Hall effect, in which electronic transport occurs in one-dimensional edge states. Electronic interactions lead to the emergence of collective transport modes characterized by an elementary charge different from the electron charge. One-dimensional transport also makes it possible to study electronic quantum optics, in which the concepts of quantum optics are transposed to the case of individual electrons.

A third research direction concerns quantum thermoelectricity, which is of interest both fundamentally and for applications. We have shown that the Seebeck coefficient can be strongly increased in the transient regime and we have highlighted the strong link between thermoelectric efficiency and mixed charge/heat correlations. We continue the study of mixed noise in different types of nanojunctions.