论文标题

将经典动力嵌入量子计算机中

Embedding classical dynamics in a quantum computer

论文作者

Giannakis, Dimitrios, Ourmazd, Abbas, Pfeffer, Philipp, Schumacher, Joerg, Slawinska, Joanna

论文摘要

我们开发了一个框架,用于在量子计算机上模拟衡量标准的千古动力系统。我们的方法通过将奇异理论与量子信息科学相结合,为经典动力学提供了新的操作者理论表示。所得的经典动力学(QECD)的量子嵌入可以使用二次数量的量子门进行有效的经典可观察物的空间呈指数较大的尺寸。 QECD框架基于一个量子特征图,用于在复制的内核Hilbert Space,$ \ Mathcal H $上通过密度运算符代表经典状态,并将经典可观察物的嵌入到$ \ Mathcal H $上的自相关操作员中。在此方案中,量子状态和可观察到的在古典系统的Koopman进化运算符的动作下单位进化。此外,借助$ \ Mathcal H $的复制属性,量子系统与基本的经典动力学相一致。为了获得指数量子的计算优势,我们将量子系统的状态投影到与$ n $ Qubits相关的$ 2^n $维张量产品Hilbert Space上的密度矩阵。通过采用离散的傅立叶变换,将有限维量子系统的进化操作员分解为张量产品形式,从而通过大小$ o(n)$的量子电路实现。此外,该电路具有状态制备阶段,也具有尺寸$ o(n)$的尺寸和量子傅立叶变换阶段的尺寸$ o(n^2)$,这使得通过标准计算基础测量可观察到可观察到的预测。我们证明这些预测的理论收敛结果是$ n \ to \ infty $。我们介绍了Qiskit AER中的模拟量子电路实验,以及IBM量子系统ONE上的实际实验。

We develop a framework for simulating measure-preserving, ergodic dynamical systems on a quantum computer. Our approach provides a new operator-theoretic representation of classical dynamics by combining ergodic theory with quantum information science. The resulting quantum embedding of classical dynamics (QECD) enables efficient simulation of spaces of classical observables with exponentially large dimension using a quadratic number of quantum gates. The QECD framework is based on a quantum feature map for representing classical states by density operators on a reproducing kernel Hilbert space, $\mathcal H $, and an embedding of classical observables into self-adjoint operators on $\mathcal H$. In this scheme, quantum states and observables evolve unitarily under the lifted action of Koopman evolution operators of the classical system. Moreover, by virtue of the reproducing property of $\mathcal H$, the quantum system is pointwise-consistent with the underlying classical dynamics. To achieve an exponential quantum computational advantage, we project the state of the quantum system to a density matrix on a $2^n$-dimensional tensor product Hilbert space associated with $n$ qubits. By employing discrete Fourier-Walsh transforms, the evolution operator of the finite-dimensional quantum system is factorized into tensor product form, enabling implementation through a quantum circuit of size $O(n)$. Furthermore, the circuit features a state preparation stage, also of size $O(n)$, and a quantum Fourier transform stage of size $O(n^2)$, which makes predictions of observables possible by measurement in the standard computational basis. We prove theoretical convergence results for these predictions as $n\to\infty$. We present simulated quantum circuit experiments in Qiskit Aer, as well as actual experiments on the IBM Quantum System One.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源