An exact real-space renormalization method and applications

Understand

We present a numerical method based on real-space renormalization that outputs the exact ground space of "frustration-free" Hamiltonians.

• The complexity of our method is polynomial in the degeneracy of the ground spaces of the Hamiltonians involved in the renormalization steps.
• We apply the method to obtain the full ground spaces of two spin systems.
• The first system is a spin-1/2 Heisenberg model with four-spin cyclic-exchange interactions defined on a square lattice.