Events at Physics |
Events on Friday, February 20th, 2009
- R. G. Herb Condensed Matter Seminar
- Disorder-induced superfluid-to-insulator transition in an optical lattice
- Time: 12:00 pm
- Place: 5310 Chamberlin
- Speaker: Brian DeMarco, University of Illinois at Urbana-Champaign
- Abstract: We experimentally realize the disordered Bose-Hubbard model by introducing fine-grained disorder to ultra-cold atoms confined in an optical lattice. Transport measurements reveal that the equivalent of resistivity is unaffected in the quantum critical regime if the disorder strength is less than or comparable to the Hubbard interaction energy U. For extreme disorder, i.e., much greater than U, we observe a disorder-induced superfluid-to-insulator transition.
- Host: Maxim Vavilov
- Theory/Phenomenology Seminar
- Spontaneous R-parity Violation in Supersymmetry
- Time: 2:30 pm - 3:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Sogee Spinner, UW-Madison Physics Dept.
- Physics Department Colloquium
- Experiments on Dirty Bosons
- Time: 4:00 pm
- Place: 2241 Chamberlin Hall (coffee and cookies at 3:30 pm)
- Speaker: Brian DeMarco, University of Illinois at Urbana-Champaign
- Abstract: Ultra-cold atom gases trapped in an optical lattice are now poised to make strong contributions to resolving outstanding questions in condensed matter physics. In these experiments, atom gases are cooled to temperatures below a millionth of a degree of absolute zero and confined in a crystal of light. I will talk about how we are using this system to simulate models relevant to dirty superconductors. I will report on the first experiments using optical lattices that include fine-grained disorder, including the observation of a disorder-induced superfluid-to-insulator transition.
- Host: Saffman