Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria.
Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria.
Nat Commun. 2017 Jun 22;8:15813. doi: 10.1038/ncomms15813.
There is a significant ongoing effort in realizing quantum annealing with different physical platforms. The challenge is to achieve a fully programmable quantum device featuring coherent adiabatic quantum dynamics. Here we show that combining the well-developed quantum simulation toolbox for Rydberg atoms with the recently proposed Lechner-Hauke-Zoller (LHZ) architecture allows one to build a prototype for a coherent adiabatic quantum computer with all-to-all Ising interactions and, therefore, a platform for quantum annealing. In LHZ an infinite-range spin-glass is mapped onto the low energy subspace of a spin-1/2 lattice gauge model with quasi-local four-body parity constraints. This spin model can be emulated in a natural way with Rubidium and Caesium atoms in a bipartite optical lattice involving laser-dressed Rydberg-Rydberg interactions, which are several orders of magnitude larger than the relevant decoherence rates. This makes the exploration of coherent quantum enhanced optimization protocols accessible with state-of-the-art atomic physics experiments.
在不同的物理平台上实现量子退火是一项正在进行的重要工作。挑战在于实现具有完全可编程量子动力学的相干绝热量子器件。在这里，我们展示了将成熟的里德堡原子量子模拟工具包与最近提出的莱纳-豪克-佐勒（LHZ）架构相结合，可以构建一个具有全连接伊辛相互作用的相干绝热量子计算机原型，因此也是量子退火的平台。在 LHZ 中，无限范围的自旋玻璃被映射到具有准局部四体宇称约束的自旋 1/2 格点规范模型的低能子空间。这个自旋模型可以用铷和铯原子在涉及激光修饰里德堡-里德堡相互作用的双原子光晶格中自然地模拟，这种相互作用比相关的退相干率大几个数量级。这使得使用最先进的原子物理实验探索相干量子增强优化协议成为可能。
