Research
In the early 20 century quantum mechanics led to the development of the band theory of solids. This theory explains the variery of the electronic ground states observed in nature : insulators, semi-conductors and metals. Later, in the middle of the century, superconductivity was explained in the framework of the qunatum mechanics, thanks to the BCS (Bardeen, Cooper, Schieffer) theory.
In spite of these remarkable triumphs, there are still many systems, with properties challenging our current understanding of electronic phenomena in solids. Our goal is to explore these exotic ground states of the matter.
There are strange metals such as cuprates, where strong correlations among electrons can lead to consequences as spectacular as high-temperature supeconductivity.
New orders can emerge from a macroscopic number of electrons in interactions. The identification of these electronic orders, the competition between them and their fluctuating life beyond the ordered states constitute the subject matter of our research. In the zero-temperature limit quantum mechanics dictate the rules of transition between ordered states.
As experimentalists, our main tool is to probe the response of the matter to a current heat. A current heat in a solid is always associated with a temperature gradient and often with an electric field. By carefully monitoring the thermal and the thermoelectric conductivity tensors (often at low temperatures and sometimes in presence of a strong magnetic field), we hope to reveal some signatures of these exotics electronic ground state.
We are also interested in magnetic response such as magnetic susceptibility and spin-spin correlation function.