Numerical Evidence of Emergent Symmetry in Spin-1/2 Heisenberg Chain
The antiferromagnetic Heisenberg chain is expected to have an extended symmetry, [“SU” (2)×”SU” (2)]⁄Z_2 , in the infrared limit, whose physical interpretation is that the spin and dimer order parameters form the components of a common 4-dimensional vector. Here we numerically investigate this emergent symmetry using quantum Monte Carlo simulations of a modified Heisenberg chain (the J-Q model) in which the logarithmic scaling corrections of the conventional Heisenberg chain can be avoided. We show how the two- and three-point spin and dimer correlation functions approach their forms constrained by conformal field theory as the system size increases and numerically confirm the expected effects of the extended symmetry on various correlation functions.
This talk will be based on work presented in arXiv:1803.02041.