Seminar by Michel Gingras (Univ. of Waterloo): "The Landscape Problem of Frustrated Magnetism"

Theory of Quantum Matter Unit invites you to a seminar by Prof. Michel Gingras, Department of Physics & Astronomy, University of Waterloo and Canadian Institute for Advanced Research:

• Date: Wed, Feb 19th
• Time: 10:30-11:30am
• Location: D014, Lab1

“The Landscape Problem of Frustrated Magnetism: 
Has Compelling Experimental Evidence for Order-by-Disorder at Last Been Found?”

Prof. Michel Gingras, Department of Physics & Astronomy, University of Waterloo
and  Canadian Institute for Advanced Research

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, or false vacuua, and thus a sort of landscape problem for condensed matter physicists.
Order-by-disorder (OdD) 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 antiferromagnetic systems called pyrochlore oxides.

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We hope to see many of you at the venue.

Sincerely,
Theory of Quantum Matter Unit