Exactly Solvable Model for a Deconfined Quantum Critical Point in 1D

We construct an exactly solvable lattice model for a deconfined quantum critical point (DQCP) in (1 thorn 1) dimensions. This DQCP occurs in an unusual setting, namely, at the edge of a (2 thorn 1) dimensional bosonic symmetry protected topological (SPT) phase with 7L2 x 7L2 symmetry. The DQCP describes a transition between two gapped edges that break different 7L2 subgroups of the full 7L2 x 7L2 symmetry. Our construction is based on an exact mapping between the SPT edge theory and a 7L4 spin chain. This mapping reveals that DQCPs in this system are directly related to ordinary 7L4 symmetry breaking critical points.

Automated summary

We propose an exactly solvable lattice model to study the deconfined quantum critical point (DQCP) in (1+1) dimensions, which occurs at the edge of a (2+1) dimensional bosonic symmetry protected topological (SPT) phase with 7L2 x 7L2 symmetry. The DQCP describes a transition between two gapped edges that break different 7L2 subgroups of the full 7L2 x 7L2 symmetry. This model provides an exact mapping between the SPT edge theory and a 7L4 spin chain, revealing the close relationship between DQCPs in this system and ordinary 7L4 symmetry breaking critical points.