论文标题
电子哈密顿量的单一转换，具有贝克 - 贝克 - 贝克 - 霍斯多夫扩张的精确二次截断
Unitary transformation of the electronic Hamiltonian with an exact quadratic truncation of the Baker-Campbell-Hausdorff expansion
论文作者
论文摘要
当前和近期量子硬件在电子结构问题上的应用受到量子计数，相干时间和门忠诚的极大限制。为了解决各种量子本质索（VQE）框架内的这些限制，许多最近的贡献表明，将电子哈密顿量的打扮成包含电子相关性的一部分，而其余的则由VQE状态制备所解释。我们提出了一种新的调味料计划，结合了对哈密顿隐居性的保存和贝克脑袋 - 霍斯多夫扩张的确切二次截断。新的转换被构建为反交易Pauli产品的参与线性组合（ILC）的指数。它结合了着装的哈密顿量的重要强相关效应，可以看作是一个经典的预处理步骤，减轻了随后的VQE应用程序的资源要求。与常规的量子耦合簇调味料相比，对LIH，H $ _2 $ O和N $ _2 $ o的新计算方案的评估显示，效率显着提高。
Application of current and near-term quantum hardware to the electronic structure problem is highly limited by qubit counts, coherence times, and gate fidelities. To address these restrictions within the variational quantum eigensolver (VQE) framework, many recent contributions have suggested dressing the electronic Hamiltonian to include a part of electron correlation, leaving the rest to be accounted by VQE state preparation. We present a new dressing scheme that combines preservation of the Hamiltonian hermiticity and an exact quadratic truncation of the Baker-Campbell-Hausdorff expansion. The new transformation is constructed as the exponent of an involutory linear combination (ILC) of anti-commuting Pauli products. It incorporates important strong correlation effects in the dressed Hamiltonian and can be viewed as a classical preprocessing step alleviating the resource requirements of the subsequent VQE application. The assessment of the new computational scheme for electronic structure of the LiH, H$_2$O, and N$_2$ molecules shows significant increase in efficiency compared to conventional qubit coupled cluster dressings.
