Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria.
Nature. 2011 Feb 24;470(7335):486-91. doi: 10.1038/nature09801.
The control of quantum systems is of fundamental scientific interest and promises powerful applications and technologies. Impressive progress has been achieved in isolating quantum systems from the environment and coherently controlling their dynamics, as demonstrated by the creation and manipulation of entanglement in various physical systems. However, for open quantum systems, engineering the dynamics of many particles by a controlled coupling to an environment remains largely unexplored. Here we realize an experimental toolbox for simulating an open quantum system with up to five quantum bits (qubits). Using a quantum computing architecture with trapped ions, we combine multi-qubit gates with optical pumping to implement coherent operations and dissipative processes. We illustrate our ability to engineer the open-system dynamics through the dissipative preparation of entangled states, the simulation of coherent many-body spin interactions, and the quantum non-demolition measurement of multi-qubit observables. By adding controlled dissipation to coherent operations, this work offers novel prospects for open-system quantum simulation and computation.
量子系统的控制具有基础科学意义，并有望带来强大的应用和技术。通过在各种物理系统中创建和操纵纠缠，已经在将量子系统与环境隔离并对其动力学进行相干控制方面取得了令人瞩目的进展。然而，对于开放量子系统，通过受控耦合到环境来工程化许多粒子的动力学在很大程度上仍未得到探索。在这里，我们实现了一个实验工具箱，用于模拟具有多达五个量子位（qubit）的开放量子系统。我们使用带有囚禁离子的量子计算架构，将多量子位门与光学泵浦相结合，以实现相干操作和耗散过程。我们通过耗散过程来制备纠缠态、模拟相干多体自旋相互作用以及对多量子位可观测量进行量子非破坏测量，展示了我们对开放系统动力学进行工程化的能力。通过将受控耗散添加到相干操作中，这项工作为开放系统量子模拟和计算提供了新的前景。
