CHARLA IFLYSIB VIRTUAL Viernes 21/02 · Chris Hooley · «Why does the valence bond solid start exactly where the ordered antiferromagnet stops?»

Título: Why does the valence bond solid start exactly where the ordered antiferromagnet stops?

Expositor: Chris Hooley – Centre for Fluid and Complex Systems, Coventry University, U.K.

Fecha: Viernes 21/02/2025 – 10:30 hs.

Resumen:

Suppose I take an ordered antiferromagnet, and change the magnetic field or the exchange interactions to provoke a phase transition from long-range antiferromagnetic order to a quantum short-range-ordered state such as a valence bond crystal. The symmetry properties of those two phases are completely different: the antiferromagnet breaks spin-rotation symmetry, while the valence bond crystal breaks only lattice translation symmetry. However, as soon as the antiferromagnetism goes away, the valence bond crystal order appears. Why?

In this talk, I shall explain our current (since approx. 20 years ago) understanding of the answer to that question, based on a collection of ideas that goes by the name of “deconfined quantum criticality”. I shall then briefly describe some recent work that my collaborators and I have been doing to describe this kind of phase transition in a more unified theoretical framework than has been available to date.

Solicitar link de acceso a charlas.iflysib@gmail.com