Computational scheme for the spin-12Heisenberg antiferromagnet based on an octapartite description of the square lattice

High-Spin Polaron in Lightly DopedCuO2Planes

“…This problem is difficult because of the complicated nature of the 2D AFM background, whose quantum fluctuations in the presence of doped holes were never fully captured for a large CuO 2 lattice. Recent technical developments [12] allow us to present the first such results for samples with up to 32 Cu and 64 O, in this Letter.…”

“…The partition of the S z T subspace into separate S T sectors was managed by the optimizations of Ref. [12]. Unlike there, no basis truncation was employed here for rigorous results.…”

Computational approach to a doped antiferromagnet: Correlations between two spin polarons in the lightly doped CuO2plane

“…The numerical modeling of multi-hole systems at zero temperature is challenging due to the combinatorially large Hilbert space and the fermion sign problem. In this work, we further validate a recently proposed numerical scheme 58 as an efficient and systematic way of modeling the doped AFM relevant to the lightly doped regime. We then use it to calculate the explicit wavefunctions for two holes introduced into a half-filled cluster of 32 copper and 64 oxygen sites with periodic boundary condition.…”

“…We have previously proposed an efficient numerical approach for the modeling of antiferromagnets, 58 upon which we will build here. For completeness, we first briefly review the undoped scenario 58 -here the system is described by AFM Heisenberg superexchange between neighbor Cu spins, see Eq.…”

“…In Ref. 58 we postulated apriorily that the subspace with C S = 1 4 captures the essence of the wavefunction, and then showed that the convergence is exponential as C S is tuned from zero to unity and that C S = 1 4 is indeed the "sweet spot".…”