Title: The 3D Plaquette Ising Model, subsystem symmetries and fractons

Abstract: A fracton is an emergent topological quasiparticle excitation which has restricted mobility. Interest in models possessing such excitations was piqued by work by Pretko and Vijay, Haah and Fu (VHF) around 2016, though they implicitly existed in other models defined earlier.In their paper VHF formulated the so-called X-cube model, which had fractonic excitations and pointed out its relation via a duality to a spin model with a sub-system symmetry – the 3D plaquette Ising model, an old favourite of mine.  In the talk we will look at both the classical and quantum versions of the 3D plaquette Ising model. In the classical case we discuss the unusual scaling properties of its first order phase transition due to the presence of a subsystem symmetry and the nature of the ordered phase. In the quantum case we contrast the nature of the quasiparticle excitations in the dual X-cube model  (fractonic) with those in the 2D toric code (anyonic).

Talk – Video

Talk – Slides