Iterative Qubit Coupled Cluster using only Clifford circuits

Understand

The performance of quantum algorithms for ground-state energy estimation is directly impacted by the quality of the initial state, where quality is traditionally defined in terms of the overlap of the input state with the target state.

• An ideal state preparation protocol can be characterized by being easily generated classically and can be transformed to a quantum circuit with minimal overhead while having a significant overlap with the targeted eigenstate of a given Hamiltonian.
• We propose a method that meets these requirements by introducing a variant of the iterative qubit coupled cluster (iQCC) approach, which exclusively uses Clifford circuits.
• These circuits can be efficiently simulated on a classical computer, with polynomial scaling according to the Gottesman-Knill theorem.