Improving the accuracy of quantum computational chemistry using the transcorrelated method

TL;DR

This paper demonstrates that the transcorrelated method, combined with quantum algorithms for imaginary time evolution, can improve the accuracy and reduce resource requirements for quantum computational chemistry calculations.

Contribution

It introduces a quantum-compatible implementation of the transcorrelated method to enhance electron correlation treatment in quantum chemistry.

Findings

Reduced computational resources for accurate energies.

Effective handling of non-Hermitian Hamiltonians on quantum computers.

Improved accuracy in electronic structure calculations.

Abstract

Accurately treating electron correlation in the wavefunction is a key challenge for both classical and quantum computational chemistry. Classical methods have been developed which explicitly account for this correlation by incorporating inter-electronic distances into the wavefunction. The transcorrelated method transfers this explicit correlation from the wavefunction to a transformed, non-Hermitian Hamiltonian, whose right-hand eigenvectors become easier to obtain than those of the original Hamiltonian. In this work, we show that the transcorrelated method can reduce the resources required to obtain accurate energies from electronic structure calculations on quantum computers. We overcome the limitations introduced by the non-Hermitian Hamiltonian by using quantum algorithms for imaginary time evolution.