论文标题
将统一的统一耦合簇扩展到三重激发
Extension of the Trotterized Unitary Coupled Cluster to Triple Excitations
论文作者
论文摘要
Trotter的单一耦合群集单和双（UCCSD）Ansatz最近由于其在量子计算机上的变异量子量化量子层（VQE）分子模拟而引起了兴趣。但是，当分子的大小增加时，UCCSD变得不那么有趣，因为它无法达到足够的精度。因此，必须恢复UCC缺失的相关效应。在这封信中，我们通过添加（true）triple t激发UCCSDT扩展了Trotterized UCC方法。我们还包括自旋和轨道对称性。实际上，实际上，这些后来有助于减少不必要的电路激发，从而加速优化过程，从而可以解决较大的分子。我们最初的数值测试（12-14 QUB）表明，UCCSDT在标准UCCSD方面至少提高了至少两端的幅度。总体而言，UCCSDT ANSATZ被证明可以达到化学精度，并与CCSD（T）金标准的量子化学方法具有竞争力。
The Trotterized Unitary Coupled Cluster Single and Double (UCCSD) ansatz has recently attracted interest due to its use in Variation Quantum Eigensolver (VQE) molecular simulations on quantum computers. However, when the size of molecules increases, UCCSD becomes less interesting as it cannot achieve sufficient accuracy. Including higher-order excitations is therefore mandatory to recover the UCC's missing correlation effects. In this Letter, we extend the Trotterized UCC approach via the addition of (true) Triple T excitations introducing UCCSDT. We also include both spin and orbital symmetries. Indeed, in practice, these later help to reduce unnecessarily circuit excitations and thus accelerate the optimization process enabling to tackle larger molecules. Our initial numerical tests (12-14 qubits) show that UCCSDT improves the overall accuracy by at least two-orders of magnitudes with respect to standard UCCSD. Overall, the UCCSDT ansatz is shown to reach chemical accuracy and to be competitive with the CCSD(T) gold-standard classical method of quantum chemistry.
