Finite-temperature symmetric tensor network for spin-1/2 Heisenberg antiferromagnets on the square lattice

Finite-temperature symmetric tensor network for spin-1/2 Heisenberg antiferromagnets on the square lattice

Blog Article

Within the tensor network framework, the (positive) thermal density operator can be approximated by a double layer of infinite Projected Entangled Pair Operator (iPEPO) coupled via ancilla degrees of elliot pecan tree for sale freedom.To investigate the thermal properties of the spin-1/2 Heisenberg model on the square lattice, we introduce a family of fully spin-$SU(2)$ and lattice-$C_{4v}$ symmetric on-site tensors (of bond dimensions $D=4$ or $D=7$) and a plaquette-based Trotter-Suzuki decomposition of the imaginary-time evolution operator.A variational optimization is performed on the plaquettes, using a full (for $D=4$) or simple (for $D=7$) environment obtained from the single-site Corner Transfer Matrix Renormalization Group fixed point.The method is benchmarked by a comparison to quantum Monte Carlo in popularfilm.blog the thermodynamic limit.Although the iPEPO spin correlation length starts to deviate from the exact exponential growth for inverse-temperature $eta gtrsim 2$, the behavior of various observables turns out to be quite accurate once plotted w.

r.t the inverse correlation length.We also find that a direct $T=0$ variational energy optimization provides results in full agreement with the $eta ightarrowinfty$ limit of finite-temperature data, hence validating the imaginary-time evolution procedure.Extension of the method to frustrated models is described and preliminary results are shown.