The major strength of the LPS is its contribution to fundamental research in condensed matter science, both in hard and soft matter.

Being a joint CNRS-Université Paris-Sud research unit (Unité Mixte de Recherche – UMR), the LPS has diverse missions: the improvement and development of knowledge, education by and for research, the exploitation of the results of research and the diffusion of scientific and technical information. The major strength of the LPS is its contribution to fundamental research in condensed matter science, both in hard and soft matter.

Research at the LPS is structured along three principal axes involving roughly equal numbers of researchers: Novel Electronic States of Matter, Condensed Matter Physics in Reduced Dimensions and Soft Condensed Matter and Biophysics.

In the first axis, Novel Electronic States of Matter, both experimental and theoretical studies are concerned with quantum and correlated systems. This has been a particularly active area for many years. Its vitality comes from the regular discovery of new systems with unexpected properties sometimes opening the way to promising applications. The LPS has made notable contributions in this area, principally concerning fundamental aspects of the physics of these systems. Certain recent developments have arisen from strong interactions with laboratories located on the nearby Saclay Plateau region.

The second axis, Condensed Matter Physics in Reduced Dimensions, deals with “nanoscience” considered in a broad sense. Phenomena are studied from the point of view of fundamental properties when the dimensions of an object become as small as certain characteristic distances (coherence length, mean free path, etc.). Three main research areas have been developed: the structure and electronic or dynamical properties of nano-objects, nanomagnetism and coherent transport at the mesoscopic scale. In nanoscience, the fabrication, structural assembly, characterisation and study of samples requires specific experimental techniques. While some of these are available in the LPS, the contribution from Large Scale Facilities, nanotechnology centres and platforms is essential.

In the third axis, Soft Condensed Matter and Biophysics, research subjects range from complex systems to living tissue, cells, viruses or DNA, from liquid crystals to foams, but also polymers or nanoparticles. These physics studies lie on the frontier between chemical physics and biology and the systems involved are often governed by a large number of interactions giving rise to cooperative phenomena and complex macroscopic behaviour. They require various innovative experimental methods, some of which have been developed in-house, and they rely on collaborations for theoretical modelling and numerical simulations. Beyond the fundamental aspects of this research, the scientific activities in this area are, on occasion, linked to industrial applications in fields as diverse as foodstuffs, petro-chemicals, cosmetics or medical applications.

The LPS Theory Group has developed numerous research themes within the three axes of the Laboratory, occasionally in collaboration with experimentalists. The group also has its own activities, in new areas that go beyond those of the axes. In particular, theoreticians focus on the rapid development of the physics of cold atoms and its links with condensed matter systems. The possibility of making new unattainable physical situations in condensed matter has stimulated new research topics within the group. For example, the ability to build a network of cold atoms that simulates graphene under stress has highlighted the fusion of Dirac points in a two-dimensional crystal, a scenario predicted and modelled in the laboratory.