Physics Department Colloquia |
Events During the Week of April 12th through April 19th, 2015
Monday, April 13th, 2015
- No events scheduled
Tuesday, April 14th, 2015
- No events scheduled
Wednesday, April 15th, 2015
- No events scheduled
Thursday, April 16th, 2015
- No events scheduled
Friday, April 17th, 2015
- Has Compelling Experimental Evidence for Order-by-Disorder at Last Been Found in a Frustrated Magnetic Material?
- Time: 3:30 pm - 4:30 pm
- Place: 2241 Chamberlin Hall (coffee at 4:30 pm)
- Speaker: Michel Gingras, University of Waterloo
- Abstract: In some magnetic systems, known as frustrated magnets, the lattice geometry or the competition between different spin-spin interactions can lead to a sub-exponentially large number of accidentally degenerate classical ground states. Order-by-disorder (ObD) is a concept of central importance in the field of frustrated magnetism. Saddled with large accidental degeneracies, a subset of states, those that support the largest quantum and/or thermal fluctuations, may be selected to form true long-range order. ObD has been discussed extensively on the theoretical front for over 30 years and proposed to be at play in a number of experimental settings. Unfortunately, convincing demonstrations of OBD in real materials have remained scarce. In this talk, I will review the phenomena of thermal and quantum of order-by-disorder and discuss how recent work may have evinced compelling evidence for ObD in some frustrated pyrochlore oxide antiferromagnetic materials.
- Host: Sue Coppersmith