“Statistical Physics and Condensed Matter” Group

Research Teams

The “Statistical Physics and Condensed Matter” Group brings together the following teams:

• Statistical Physics and Complex Systems
• Nanophysics

The statistical mechanics and condensed matter group encompasses two main themes: statistical physics and complex systems on one hand, and nanophysics on the other.

The first theme involves three axes covering a large part of statistical physics. The first deals with rigorous statistical mechanics and in particular the study of phase transition phenomena. The second deals with the statistical mechanics of open quantum systems out of equilibrium, and the third with the statistical physics of complex systems. The “boundaries” between these three research axes are quite arbitrary and largely permeable, and many members of the team are active in at least two of them. Methods range from rigorous mathematical approaches to numerical simulations, as well as the analysis of empirical data through the standard approximation tools of statistical physics. Furthermore, the team develops interfaces both within and outside the field of physics.

The second theme of the group focuses on quantum transport in mesoscopic systems and nano-objects: these systems are small enough in size and temperature for charge carrier propagation to occur coherently. The main devices studied are:

• Superconducting and hybrid systems, where the fundamental nature of a Cooper pair (2 entangled electrons) gives rise to unique properties (Josephson current, Cooper pair splitting, etc.).
• Electron transport properties in the Quantum Hall Effect, where chiral edge states provide a tool to study quantum electronics, with single electrons replacing single photons in interference experiments. Coulomb interaction in these 1D systems also gives rise to non-integer charge collective excitations, described by the Luttinger model.
• Thermoelectric quantum transport, where the Seebeck coefficient is studied in the mesoscopic regime, as well as mixed correlations of charge and heat currents.

Statistical Physics and Complex Systems

The team’s activities cover a wide spectrum in statistical physics, ranging from rigorous studies of phase transitions to open quantum systems, complex networks, and their interdisciplinary applications.

Nanophysics

The nanophysics team theoretically studies quantum electronic transport (electronic or thermal current and its fluctuations) in nano- and mesoscopic systems: quantum dots, semiconductor nanowires, and superconductors.