Beyond MP2 initialization for unitary coupled cluster quantum circuits

Understand

The unitary coupled cluster (UCC) ansatz is a promising tool for achieving high-precision results using the variational quantum eigensolver (VQE) algorithm in the NISQ era.

• However, results on quantum hardware are thus far very limited and simulations have only accessed small system sizes.
• We advance the state of the art of UCC simulations by utilizing an efficient sparse wavefunction circuit solver and studying systems up to 64 qubits.
• Here we report results obtained using this solver that demonstrate the power of the UCC ansatz and address pressing questions about optimal initial parameterizations and circuit construction, among others.