Block-Spin Approach to Electron Correlations

TL;DR

This paper introduces a block-spin basis expansion for quantum lattice systems, enabling efficient truncation of the Hilbert space while preserving accuracy, demonstrated on an antiferromagnetic spin chain.

Contribution

It presents a novel block-spin expansion method that effectively reduces Hilbert space size with high accuracy for quantum many-body systems.

Findings

Severe Hilbert space truncation achieved with high accuracy.

Method applied successfully to antiferromagnetic spin-1/2 chain.

Demonstrates efficiency of block-spin basis in quantum systems.

Abstract

We consider an expansion of the ground state wavefunction of quantum lattice many-body systems in a basis whose states are tensor products of block-spin wavefunctions. We demonstrate by applying the method to the antiferromagnetic spin-1/2 chain that by selecting the most important many-body states the technique affords a severe truncation of the Hilbert space while maintaining high accuracy.