O.M. Stewart Colloquium Series

Wednesday, March 8, 2017 4:00pm

120 Physics Building

Departments: 

University of Edinburgh

Chris Stock, University of Edinburgh, Scotland, presents, "Solitary magnons and edge states in CaFe2O4," on Wednesday, March 8 at 4 p.m. in Room 120, Physics Building.  Refreshments will be served at 3:30pm in 223A Library.

CaFe2O4 is an anisotropic classical S=5/2 antiferromagnet with two competing magnetic ground states separated by static antiphase boundaries.  We have applied neutron scattering to study the structure and dynamics of this antiferromagnet. These measurements reveal that the antiphase boundaries separating the competing magnetic orders are confining, resulting in a hierarchy of discrete and countable magnetic excitations, termed solitary magnons. The antiphase boundaries also host magnetic edge states which can be understood in terms of localized dimer excitations. These edge states have a strong analogy to solitons in the polymer polyacetylene. CaFe2O4 is an example of where confinement and spatially localized solitons can exist in a classical magnet with competing ground states.