标题： 借助场媒介的Unruh--DeWitt量子比特的通用量子计算 显示英文标题

标题： Universal Quantum Computing with Field-Mediated Unruh--DeWitt Qubits

摘要： 一个通用量子门集是量子计算理论的重要组成部分，但在正在发展的相对论量子信息（RQI）理论中却不存在。然而，Unruh-DeWitt（UDW）探测器形式主义可以被提升到量子比特和量子场之间的幺正门，并允许在量子Shannon理论中的RQI应用，例如通过场媒介的量子信道中的互信息、相干信息和量子容量。 最近，在二维量子材料中提出了UDW风格量子比特的实验实现，但它们作为量子技术的价值，包括量子通信和计算，尚不清楚，特别是因为场引入了许多退相干途径。 我们引入了量子比特与场之间的受控幺正UDW逻辑门，这些门类似于两量子比特的CNOT门。 然后我们将这一形式扩展，以展示量子态传输（QST）（两个CNOT门）和SWAP（三个CNOT门）通道。 我们使用钻石距离来说明这些量子操作门的性能，钻石距离是一种衡量量子信道之间可区分性的指标。 像钻石距离这样的可区分性度量允许对通过UDW探测器的场媒介转换和局部量子力学操作之间进行严格的比较，从而量化UDW探测器在量子技术应用中的性能。 利用受控幺正量子比特-场相互作用，我们定义了CNOT门的确切形式。 通过这项技术，我们也定义了与Hadamard$H$、$S$和$T$门相关的量子场媒介单量子比特操作。 因此，简单的UDW探测器设置能够提供已知的实现通用量子计算的一组门。 显示英文摘要

摘要： A set of universal quantum gates is a vital part of the theory of quantum computing, but is absent in the developing theory of Relativistic Quantum Information (RQI). Yet, the Unruh--DeWitt (UDW) detector formalism can be elevated to unitary gates between qubits and quantum fields and has allowed RQI applications in quantum Shannon theory, such as mutual information, coherent information, and quantum capacity in field-mediated quantum channels. Recently, experimental realizations of UDW-style qubits have been proposed in two-dimensional quantum materials, but their value as a quantum technology, including quantum communication and computation, is not yet clear, especially since fields introduce many avenues for decoherence. We introduce controlled-unitary UDW logic gates between qubit and field that are comparable to the two-qubit CNOT gate. We then extend this formalism to demonstrate Quantum State Transfer (QST) (two CNOT gates) and SWAP (three CNOT gates) channels. We illustrate the performance of these quantum operation gates with the diamond distance, a measure of distinguishability between quantum channels. Distinguishability measures like diamond distance allow for a rigorous comparison between field-mediated transduction through UDW detectors and local quantum mechanical operations and so quantify the performance of UDW detectors in quantum technological applications. Using the controlled-unitary qubit-field interactions we define an exact form of the CNOT gate. With this technique we also define quantum field-mediated single qubit operations associated with the Hadamard $H$, the $S$, and $T$ gates. Thus, UDW detectors in simple settings enable a collection of gates known to provide universal quantum computing.