1 research outputs found
Exploring Parameter Redundancy in the Unitary Coupled-Cluster Ansatze for Hybrid Variational Quantum Computing
One of the commonly used chemical-inspired approaches in variational quantum
computing is the unitary coupled-cluster (UCC) ansatze. Despite being a
systematic way of approaching the exact limit, the number of parameters in the
standard UCC ansatze exhibits unfavorable scaling with respect to the system
size, hindering its practical use on near-term quantum devices. Efforts have
been taken to propose some variants of UCC ansatze with better scaling. In this
paper we explore the parameter redundancy in the preparation of unitary
coupled-cluster singles and doubles (UCCSD) ansatze employing spin-adapted
formulation, small amplitude filtration, and entropy-based orbital selection
approaches. Numerical results of using our approach on some small molecules
have exhibited a significant cost reduction in the number of parameters to be
optimized and in the time to convergence compared with conventional UCCSD-VQE
simulations. We also discuss the potential application of some machine learning
techniques in further exploring the parameter redundancy, providing a possible
direction for future studies