Nested Cluster Algorithm for Frustrated Quantum Antiferromagnets

Understand

Simulations of frustrated quantum antiferromagnets suffer from a severe sign problem.

• We solve the ergodicity problem of the loop-cluster algorithm in a natural way and apply a powerful strategy to address the sign problem.
• For the spin 1/2 Heisenberg antiferromagnet on a kagome and on a frustrated square lattice, a nested cluster algorithm eliminates the sign problem for large systems.
• The method is applicable to general lattice geometries but limited to moderate temperatures.