论文标题
使用立方相门的全光量子计算
All-optical quantum computing using cubic phase gates
论文作者
论文摘要
如果可以使用合适的量子光学相互作用，以非线性的方式转换光场模式运算符，全光音平台可能是实现量子计算机的最强竞争者之一。与其他基于物质的（固态或原子）平台不同，可以在室温和高时钟速率（GHz或原则上甚至THZ）下操作光子Qubits。此外，最近的连续变化时间域方法非常可扩展。此外，虽然可以直接处理单光子量子尺，但使用所谓的骨器代码可以将“更明亮”的逻辑量子嵌入单个振荡器模式中，以进行原始耐受耐受性的处理。在本文中，我们展示了如何仅使用光束拆分器与单模立方相对于合理数字的单模立方体门一起实现全光，通用和耐断层量子计算的元素，以及可能脱机挤压状态或单次资源。我们的方法基于结合精确门分解和近似Trotterization的分解技术。这允许某些非线性连续变量多模门有效地分解到基本门中，其中所需的几立方门甚至可能是弱或所有相同的，从而促进了潜在的实验。最终的门操作包括两种模式控制的相位旋转和三模式Rabi-Type Hamiltonian大门，这些大门可用于实现高保真单光子两倍纠缠的大门，或者作为波斯多尼克代码示例，创建高质量的Gottesman-Kiteman-Kitaev-preskill State。我们期望我们在各种应用程序中的一般使用方法，包括依靠四分之一的Kerr类型相互作用的应用程序。
If suitable quantum optical interactions were available, transforming optical field mode operators in a nonlinear fashion, the all-photonics platform could be one of the strongest contenders for realizing a quantum computer. Unlike other, matter-based (solid-state or atomic) platforms, photonic qubits can be operated at room temperature and high clock rates (GHz or, in principle, even THz). In addition, recent continuous-variable time-domain approaches are extremely well scalable. Moreover, while single-photon qubits may be processed directly, "brighter" logical qubits may be embedded in individual oscillator modes, using so-called bosonic codes, for an in-principle fault-tolerant processing. In this paper, we show how elements of all-optical, universal, and fault-tolerant quantum computation can be implemented using only beam splitters together with single-mode cubic phase gates in reasonable numbers, and possibly off-line squeezed-state or single-photon resources. Our approach is based on a decomposition technique combining exact gate decompositions and approximate Trotterization. This allows for efficient decompositions of certain nonlinear continuous-variable multimode gates into the elementary gates, where the few cubic gates needed may even be weak or all identical, thus facilitating potential experiments. The final gate operations include two-mode controlled phase rotation and three-mode Rabi-type Hamiltonian gates, which are shown to be employable for realizing high-fidelity single-photon two-qubit entangling gates or, as a bosonic-code example, creating high-quality Gottesman-Kitaev-Preskill states. We expect our method of general use with various applications, including those that rely on quartic Kerr-type interactions.
