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Tuesday, April 24, 2018
2:00 p.m.
Harvard University
Department of Physics
17 Oxford Street, Cambridge, MA
Jefferson 250 David Lee Distinguished Professor
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. |