Test of the unitary coupled-cluster variational quantum eigensolver for a simple strongly correlated condensed-matter system

Understand

The variational quantum eigensolver has been proposed as a low-depth quantum circuit that can be employed to examine strongly correlated systems on today's noisy intermediate-scale quantum computers.

• We examine details associated with the factorized form of the unitary coupled-cluster variant of this algorithm.
• We apply it to a simple strongly correlated condensed-matter system with nontrivial behavior---the four-site Hubbard model at half filling.
• This work show some of the subtle issues one needs to take into account when applying this algorithm in practice, especially to condensed-matter systems.