1] Department of Mathematical Physics, National University of Ireland, Maynooth, Ireland [2] Institute for Quantum Computing and Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Institute for Quantum Computing and Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
Nature. 2014 Jun 19;510(7505):351-5. doi: 10.1038/nature13460. Epub 2014 Jun 11.
Quantum computers promise dramatic advantages over their classical counterparts, but the source of the power in quantum computing has remained elusive. Here we prove a remarkable equivalence between the onset of contextuality and the possibility of universal quantum computation via 'magic state' distillation, which is the leading model for experimentally realizing a fault-tolerant quantum computer. This is a conceptually satisfying link, because contextuality, which precludes a simple 'hidden variable' model of quantum mechanics, provides one of the fundamental characterizations of uniquely quantum phenomena. Furthermore, this connection suggests a unifying paradigm for the resources of quantum information: the non-locality of quantum theory is a particular kind of contextuality, and non-locality is already known to be a critical resource for achieving advantages with quantum communication. In addition to clarifying these fundamental issues, this work advances the resource framework for quantum computation, which has a number of practical applications, such as characterizing the efficiency and trade-offs between distinct theoretical and experimental schemes for achieving robust quantum computation, and putting bounds on the overhead cost for the classical simulation of quantum algorithms.
量子计算机有望在性能上超越传统计算机，但量子计算的能力来源一直难以捉摸。在这里，我们通过“魔法态”蒸馏证明了语境相关性和通用量子计算的可能性之间的显著等价性，这是实验实现容错量子计算机的主要模型。这是一个概念上令人满意的联系，因为语境相关性排除了量子力学的简单“隐变量”模型，为独特的量子现象提供了基本特征之一。此外，这种联系为量子信息资源提供了一个统一的范例：量子理论的非局域性是一种特殊的语境相关性，而众所周知，非局域性是通过量子通信获得优势的关键资源。除了阐明这些基本问题外，这项工作还推进了量子计算的资源框架，该框架具有许多实际应用，例如刻画不同理论和实验方案实现稳健量子计算的效率和权衡，以及对量子算法的经典模拟的开销施加限制。
