Choe Shin Ho, König Robert
Department of Mathematics, School of Computation, Information and Technology, Technical University of Munich, Garching, Germany.
Munich Center for Quantum Science and Technology (MCQST), Munich, Germany.
npj Quantum Inf. 2024;10(1):132. doi: 10.1038/s41534-024-00928-4. Epub 2024 Dec 26.
We propose a fault-tolerant scheme for generating long-range entanglement at the ends of a rectangular array of qubits of length with a square cross-section of qubits. It is realized by a constant-depth circuit producing a constant-fidelity Bell-pair (independent of ) for local stochastic noise of strength below an experimentally realistic threshold. The scheme can be viewed as a quantum bus in a quantum computing architecture where qubits are arranged on a rectangular 3D grid, and all operations are between neighboring qubits. Alternatively, it can be seen as a quantum repeater protocol along a line, with neighboring repeaters placed at a short distance to allow constant-fidelity nearest-neighbor operations. To show our protocol uses a number of qubits close to optimal, we show that any noise-resilient distance- entanglement generation scheme realized by a constant-depth circuit needs at least qubits per repeater.
我们提出了一种容错方案，用于在具有 个量子比特的方形横截面且长度为 的矩形量子比特阵列两端生成长程纠缠。它由一个常数深度电路实现，该电路针对强度低于实验现实阈值的局部随机噪声产生恒定保真度的贝尔对（与 无关）。该方案可被视为量子计算架构中的量子总线，其中量子比特排列在矩形三维网格上，且所有操作都在相邻量子比特之间进行。或者，它也可被视为沿一条线的量子中继器协议，相邻中继器放置在较短距离处以允许进行恒定保真度的最近邻操作。为了表明我们的协议使用的量子比特数量接近最优，我们证明，任何由常数深度电路实现的抗噪声距离纠缠生成方案每个中继器至少需要 个量子比特。
