Thermodynamics of disordered square lattice models using NLCEs

Studying the properties of disordered quantum spin lattice models is challenging due to the exponentially growing Hilbert space and the need to carry out averages over many disorder configurations. Here, we use three different NLCE schemes, the L, rectangular, and square expansions, to study thermodynamic observables of spin models on the square lattice with continuous disorder in the bond strengths, J ∈ [-W,W]. We systematically study the effects of statistical errors on the convergence of NLCEs to the thermodynamic limit results. We demonstrate convergence down to temperatures that are a fraction of W.