University of Minnesota
School of Physics & Astronomy

Physics and Astronomy Calendar

Wednesday, November 29th 2017
4:30 pm:
CM Journal Club in Tate Hall 201-20
Speaker: Mengxing Ye
Subject: Deconfined quantum criticality

I will give an overview of the theory of deconfined quantum criticality following [1]. As an example, it shows that the quantum phase transition of the S=1/2 square lattice antiferromagnet between the Neel state (which breaks spin rotation symmetry) and the paramagnetic valence bond crystal (which preserves spin rotation but breaks lattice symmetry) is second order without fine-tuning. To achieve it, the field theory at the quantum critical point cannot be described by order parameters of either phases. I will focus on the physical picture and briefly discuss how the low energy field theory is formulated. A look at the less technical overview paper [2] is recommended.

[1] Quantum criticality beyond the Landau-Ginzburg-Wilson paradigm
[2] Deconfined Quantum Critical Points

The weekly calendar is also available via subscription to the physics-announce mailing list, and by RSS feed.