Theoretical Physics(DTP)
Physique théorique (DPT)
Ian AFFLECK
University of British Columbia
Field-induced phase transition in anisotropic Haldane gap antiferromagnetic chains
Integer spin antiferromagnetic chains, which exhibit the Haldane gap, undergo a zero temperature phase transition at a critical magnetic field at which the Zeeman energy equals the Haldane gap. This transition was shown to correspond to Bose condensation. In this seminar I will discuss this transition in the presence of anisotropic exchange interactions which change the transition to Ising type. The behavior of the energy and width of various excitations with field will be analysed using field theory, exact integrability and renormalization group techniques.
In collabaration with: F.H.L. Essler Oxford University.