New Chiral Phases of Superfluid 3He Stabilized by Anisotropic Silica Aerogel
J. Pollanen, J. I. A. Li, C. A. Collett, W. J. Gannon, W. P. Halperin and J. A. Sauls
- Address: Department of Physics & Astronomy, Northwestern University, Evanston, IL 60208
- Date: January 15, 2012
Nature Physics 8, 317-320 (2012)
A rich variety of Fermi systems condense by forming bound pairs, including high temperature and
heavy fermion superconductors, Sr2RuO4, cold atomic gases, and superfluid 3He. Some
of these form exotic quantum states having non-zero orbital angular momentum. We have discovered, in
the case of 3He, that anisotropic disorder, engineered from highly porous silica aerogel, stabilizes a
chiral superfluid state that otherwise would not exist. Additionally, we find that the chiral axis of
this state can be uniquely oriented with the application of a magnetic field perpendicular to the
aerogel anisotropy axis. At suffciently low temperature we observe a sharp transition from a uniformly
oriented chiral state to a disordered structure consistent with locally ordered domains, contrary to
expectations for a superfluid glass phase.
- Comment: 6 pages, 4 figures, with supplementary section on theoretical analysis and background.