Non-unitary operations for ground-state calculations in near term quantum computers
Abstract
We introduce a quantum Monte Carlo inspired reweighting scheme to accurately compute energies from optimally short quantum circuits. This effectively hybrid quantum-classical approach features both entanglement provided by a short quantum circuit, and the presence of an effective non-unitary operator at the same time. The functional form of this projector is borrowed from classical computation and is able to filter-out high-energy components generated by a sub-optimal variational quantum heuristic ansatz. The accuracy of this approach is demonstrated numerically in finding energies of entangled ground-states of many-body lattice models. We demonstrate a practical implementation on IBM quantum hardwares up to an 8 qubits circuit.
Keywords
Cite
@article{arxiv.1910.01830,
title = {Non-unitary operations for ground-state calculations in near term quantum computers},
author = {Guglielmo Mazzola and Pauline Ollitrault and Panagiotis Barkoutsos and Ivano Tavernelli},
journal= {arXiv preprint arXiv:1910.01830},
year = {2019}
}
Comments
5 pages + supplementary materials