Efficient Simulation of Loop Quantum Gravity: A Scalable Linear-Optical Approach
Efficient Simulation of Loop Quantum Gravity: A Scalable Linear-Optical Approach
复制标题
环量子引力的有效模拟：可扩展的线性光学方法
DOI：
10.1103/physrevlett.126.020501
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发表时间：
2021
影响因子：
8.6
通讯作者：
Han, Muxin
中科院分区：
文献类型：
--
作者：
Cohen, Lior;Brady, Anthony J.;Huang, Zichang;Liu, Hongguang;Qu, Dongxue;Dowling, Jonathan P.;Han, Muxin
在经典计算机上模拟复杂量子过程的问题催生了量子模拟领域。量子模拟器解决了经典模拟器无法解决的问题，比如玻色子采样。在物理学的另一个领域，广义相对论和量子理论的统一是我们这个时代最大的挑战之一。一种主要的方法是环路量子引力(LQG)。在这里，我们将这两个场连接起来，并设计了一个线性光学模拟器，使得光学量子门的演化可以模拟LQG的自旋泡沫振幅。研究表明，简单量子场论中计算跃迁幅度属于有界误差量子多项式时间类，这有力地表明了计算LQG跃迁幅度是经典的难题。因此，这些幅度可以用通用量子计算机有效地计算出来，唉，可能还需要几十年的时间。我们在这里提出了一种替代的特殊用途的线性光学量子计算机，可以使用现有的技术来实现。这台机器能够有效地计算这些量。这项工作开辟了一条将量子引力与量子信息联系起来的新途径，并将扩大我们对这一理论的理解。
The problem of simulating complex quantum processes on classical computers gave rise to the field of quantum simulations. Quantum simulators solve problems, such as boson sampling, where classical counterparts fail. In another field of physics, the unification of general relativity and quantum theory is one of the greatest challenges of our time. One leading approach is loop quantum gravity (LQG). Here, we connect these two fields and design a linear-optical simulator such that the evolution of the optical quantum gates simulates the spin-foam amplitudes of LQG. It has been shown that computing transition amplitudes in simple quantum field theories falls into the bounded-error quantum polynomial time class, which strongly suggests that computing transition amplitudes of LQG are classically intractable. Therefore, these amplitudes are efficiently computable with universal quantum computers, which are, alas, possibly decades away. We propose here an alternative special-purpose linear-optical quantum computer that can be implemented using current technologies. This machine is capable of efficiently computing these quantities. This work opens a new way to relate quantum gravity to quantum information and will expand our understanding of the theory.