A Quantum-Inspired Algorithm for the Factorized Form of Unitary Coupled Cluster Theory

Understand

The factorized form of unitary coupled cluster theory (UCC) is a promising wave-function ansatz for the variational quantum eigensolver algorithm.

• Here, we present a quantum inspired algorithm for UCC based on an exact operator identity for the individual UCC factors.
• We implement this algorithm for calculations of the H$_{10}$ linear chain and the H$_2$O molecule with single and double $\zeta$ basis sets to provide insights about UCC as a wave-function ansatz.
• We find that as an electronic structure method, UCC could potentially be valuable for strongly correlated systems, for which conventional coupled cluster theory has difficulties.