Browsing by Author "Dutta, Rishab"

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    Lessons from electron pairing models for postmodern quantum chemistry
    (2023-07-20) Dutta, Rishab; Scuseria, Gustavo E.
    Strong electron correlation is ubiquitous in chemistry and physics. The importance of strong correlation in diverse chemical systems and the failure of traditional electronic structure methods to capture it motivate the current work. We highlight the role of electron pairing in strong correlation and introduce conceptually appealing wavefunction ansätze that can accurately describe strong pairing interactions. Our work builds the foundations of a new generation of quantum chemistry methods which would expand the space of many-electron systems that are accurately understood.
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    State Preparation of Antisymmetrized Geminal Power on a Quantum Computer without Number Projection
    (American Chemical Society, 2023) Khamoshi, Armin; Dutta, Rishab; Scuseria, Gustavo E.
    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.