论文标题
量子状态制备无连贯的算术
Quantum state preparation without coherent arithmetic
论文作者
论文摘要
我们引入了一种多功能方法，用于制备量子状态，其幅度由某些已知功能给出。与现有方法不同，我们的方法不需要手工制作的可逆算术电路或量子表读取量的量子来编码函数值。取而代之的是，我们使用模板量子特征值转换电路将正弦函数的低成本块编码转换为所需的函数。我们的方法仅使用4个Ancilla Qubit（如果近似多项式具有明确的奇偶校验），与最新方法相比，降低了数量的Qubit计数，则提供降低的量顺序，而如果函数可以通过多项式或傅立叶近似值很好地表示，则使用相似数量的门。像黑盒方法一样，我们方法的复杂性取决于该函数的“ L2-Norm填充分数”。我们证明了我们方法的算法实用性，包括准备高斯和凯撒窗口。
We introduce a versatile method for preparing a quantum state whose amplitudes are given by some known function. Unlike existing approaches, our method does not require handcrafted reversible arithmetic circuits, or quantum table reads, to encode the function values. Instead, we use a template quantum eigenvalue transformation circuit to convert a low cost block encoding of the sine function into the desired function. Our method uses only 4 ancilla qubits (3 if the approximating polynomial has definite parity), providing order-of-magnitude qubit count reductions compared to state-of-the-art approaches, while using a similar number of gates if the function can be well represented by a polynomial or Fourier approximation. Like black-box methods, the complexity of our approach depends on the 'L2-norm filling-fraction' of the function. We demonstrate the algorithmic utility of our method, including preparing Gaussian and Kaiser window states.
