Professor Valles does research in experimental condensed matter physics, in the areas of: superconductivity; electron correlation effects in disordered metals and nanostructures; and in using magnetic fields as a new tool for cell biology and biopolymerization.
Valles’ group performs research in two distinct areas: low temperature condensed matter physics and biological physics.
The condensed matter physics research focuses on uncovering and exploring the properties of the possible phases, such as superconducting, insulating, or magnetic, that metals assume at very low temperatures. Which phase emerges in a given system can be determined by a subtle interplay of its geometry, its microscopic structure and whether or not it is in a magnetic field. Most recently, Valles has focused on films of metals that are so thin that they exhibit two dimensional properties. Some of these come with their own nanostructure, while others are patterned with features on the scale of nanometers. The specific topics that this research addresses are the two dimensional superconductor to insulator and superconductor to metal transitions, localization phenomena, proximity effects in mesoscopic systems, and the physics of thin film growth on low temperature and nanostructured substrates.
Biological physics work in the Valles lab has been directed at developing the use of intense, static magnetic fields as a means of manipulating biological systems. They have shown that cell division in frog eggs, the swimming of microorganisms, and biopolymerization phenomena can be modified and investigated with static magnetic fields.