Description
Simulating higher-dimensional lattice models remains a significant challenge, spurring interest in advanced renormalization group (RG) methods for tensor-network states. One such model we study here is the two-dimensional XY model. This theory has been understood greatly and undergoes a BKT type of phase transition. Adding an extra spin-nematic interaction term with period, the modified XY model called generalized XY model, now contains both integer vortices and half-integer vortices excitations. These vortices govern the critical behavior and produce rich physics even in two dimensions. We study the transition behavior between the integer vortex binding and half-integer vortex binding phases and how this transition line merges into two BKT transition lines using the higher-order tensor renormalization group method a promising technique to produce improved results.
