The New Phases of Superfluid 3He Confined in Aerogels
W. P. Halperin and Jeevak Parpia and
J. A. Sauls
- Address: Department of Physics & Astronomy, Northwestern University, Evanston, IL 60208
- Date: February 27, 2018
Physics Today (to be published)
The 2017 Fritz London Memorial Prize in Low Temperature Physics highlighted the remarkable new superfluid phases of liquid Helium-Three (3He - the light isotope of Helium) that result from confinement of 3He within highly porous random solids. The orginial discoveries were with 3He infused into a form of glass (SiO2) called silica aerogel. The latter is a remarkable material itself, a gossamer solid with fractal correlations and a density that is ∼1/100th that of everyday glass. As for the Helium liquids they are among nature's finer gifts to physics, in part because they exist in the liquid state down to the absolute zero of temperature. This has provided us with a liquid whose properties in aggregate are governed by the laws of quantum mechanics, i.e the Helium liquids are quantum liquids, a field of inquiry pioneered by Fritz London.
The discovery of superfluidity of liquid 3He infused into silica aerogel opened new directions in the study of disorder on BCS condensates with complex broken symmetry phases. Much more research has been carried out in many laboratories since the initial discoveries. In what follows we highlight some of the research on 3He infused into high-porosity disordered solids, particularly the discovery and control of new superfluid phases.
- Comment: 7 pages, 5 figures