COMPUTER-IMPLEMENTED METHOD OF SOLVING A HAMILTONIAN

摘要

The computer implemented method of solving a Hamiltonian can include performing, in a tensor network contracting a plurality of tensors in the network, a Lanczos method acting on the uncontracted tensors, the Lanczos method including evaluating a recursive relation of an equation including using the equation at least two times, forming a block tridiagonal matrix having a block size greater than one, based on the recursive relation, and diagonalizing the block tridiagonal matrix to obtain new tensors and energy levels of the tensor network, wherein at least one of the uncontracted tensors of the network has an index for the group of excitations; and solving for the rest of the tensor network, yielding an energy level solution of the Hamiltonian, outputting the energy level solution.