论文标题
量子轨道最小化方法用于量子计算机上的激发状态计算
Quantum Orbital Minimization Method for Excited States Calculation on Quantum Computer
论文作者
论文摘要
我们提出了一种量子杂种杂种算法，即量子轨道最小化方法（QOMM），用于获得Hermitian操作员的基态和低覆盖激发态。给定的代表本征态的参数化ANSANZ电路，Qomm在轨道最小化方法中实现了量子电路，以表示目标函数，并采用经典优化器，以最大程度地减少Ansatz电路中参数的目标函数。该目标函数具有隐式嵌入的正交性，这允许Qomm将不同的ANSATZ电路应用于每个参考状态。我们进行数值模拟，试图找到$ \ text {h} _ {2} $，$ \ text {lih} $的激发态，以及一个由4个以STO-3G基础和UCCSD Ansatz Circuits以方格安排的氢原子组成的玩具模型。将数值结果与现有激发态方法进行比较，Qomm不太容易陷入本地最小值，并且可以与更浅的Ansatz电路获得收敛。
We propose a quantum-classical hybrid variational algorithm, the quantum orbital minimization method (qOMM), for obtaining the ground state and low-lying excited states of a Hermitian operator. Given parameterized ansatz circuits representing eigenstates, qOMM implements quantum circuits to represent the objective function in the orbital minimization method and adopts classical optimizer to minimize the objective function with respect to parameters in ansatz circuits. The objective function has orthogonality implicitly embedded, which allows qOMM to apply a different ansatz circuit to each reference state. We carry out numerical simulations that seek to find excited states of the $\text{H}_{2}$, $\text{LiH}$, and a toy model consisting of 4 hydrogen atoms arranged in a square lattice in the STO-3G basis and UCCSD ansatz circuits. Comparing the numerical results with existing excited states methods, qOMM is less prone to getting stuck in local minima and can achieve convergence with more shallow ansatz circuits.
