Tuesday, April 24, 2018
Department of Physics
17 Oxford Street, Cambridge, MA
Texas A&M U
"H atoms in Solid Molecular Hydrogen: To BEC or not to BEC"
Condensed Matter Physics SPECIAL SEMINAR
Electron Spin Resonance experiments at temperatures between 1.5 K and 0.09 K in a magnetic field of 4.6 Tesla in thin films (of order 0.1 microns) containing atomic and molecular hydrogen have been performed. The electron spins of the H atoms are already highly polarized in this temperature and field range. Evidence is provided to show that a phase separation occurs into phases with high and low concentrations of H atoms, respectively. The high atom concentration phase shows a large nuclear polarization (far in excess of that required by the Boltzmann distribution) possibly attributable to strong Bose-Einstein correlations. If the H atom concentration is high enough, this could lead to a liquid phase which may exhibit superfluid behavior or a topologically ordered phase in the spirit of the Kosterlitz-Thouless transition.
Free and open to the public.