Many materials discovered during the last thirty years, such as rare earth or actinide compounds, superconducting cuprates, organic conductors, fullerenes, cobaltates, and geometrically frustrated compounds, have fundamental states and have laws of behaviour (superconductivity with an exotic symmetry order parameter, orbital orders), which can no longer be described by simple band theory approaches.
This is due to strong interactions between electrons, which often arise by the proximity of an insulating Mott state having original magnetic properties. Novel theoretical concepts are required for describing the nature of the metal state of these systems. The frontiers of this field today encompass artificial solids formed by atomic condensates trapped in optical lattices. The Triangle de la Physique will offer the possibility of promoting the remarkable position of the Plateau de Saclay, which concentrates in these fields internationally prestigious teams covering the whole of the spectrum ranging from the synthesis of materials to their theoretical study. It is expected to promote mastery and development of advanced experimental methods in its laboratory (structural studies, low temperatures, high pressures, local spectrometries: NMR, STM, EELS, magnetic and transport measurements) as well as around the large instruments (polarized neutrons at the LLB, resonant diffraction, ARPES, RIX at SOLEIL).
These approaches are essential for revealing and analyzing the original behaviours of correlated systems, thereby opening the path to the elaboration of materials with specific functions, and certainly to original applications in the medium term. The interdisciplinarity of the centre should reinforce links with solid-state chemists, promote developments of theoretical methods towards calculations that into account both correlation effects and realistic characteristics of particular materials and reinforce exchanges and competitiveness of our teams in a background of strong international competition.