State Preparation of Antisymmetrized Geminal Power on a Quantum Computer without Number Projection
The antisymmetrized geminal power (AGP) is equivalent to the number projected Bardeen–Cooper–Schrieffer (PBCS) wave function. It is also an elementary symmetric polynomial (ESP) state. We generalize previous research on deterministically implementing the Dicke state to a state preparation algorithm for an ESP state, or equivalently AGP, on a quantum computer. Our method is deterministic and has polynomial cost, and it does not rely on number symmetry breaking and restoration. We also show that our circuit is equivalent to a disentangled unitary paired coupled cluster operator and a layer of unitary Jastrow operator acting on a single Slater determinant. The method presented herein highlights the ability of disentangled unitary coupled cluster to capture nontrivial entanglement properties that are hardly accessible with traditional Hartree–Fock based electronic structure methods.
Khamoshi, Armin, Dutta, Rishab and Scuseria, Gustavo E.. "State Preparation of Antisymmetrized Geminal Power on a Quantum Computer without Number Projection." The Journal of Physical Chemistry A, 127, no. 18 (2023) American Chemical Society: 4005-4014. https://doi.org/10.1021/acs.jpca.3c00525.