Practical implementation of arbitrary nonlocal controlled-unitary gate via indefinite causal order

Fuente: arXiv
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Main Authors: Liu, Wen-Qiang, Zheng, Zi-Han, Yin, Zhang-Qi, Wei, Hai-Rui
Format: Preprint
Published: 2026
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author Liu, Wen-Qiang
Zheng, Zi-Han
Yin, Zhang-Qi
Wei, Hai-Rui
author_facet Liu, Wen-Qiang
Zheng, Zi-Han
Yin, Zhang-Qi
Wei, Hai-Rui
contents Quantum gate teleportation enables the implementation of nonlocal quantum operations without direct interactions between distant nodes. We propose an efficient protocol for implementing arbitrary controlled-unitary (CU) gates acting on two spatially separated parties via indefinite causal order (ICO). By establishing a maximally entanglement between two remote nodes and coherently superposing orders of single-qubit gates, our protocol circumvents the drawback of complex local two-qubit operations. This ICO-based approach enables full programmability of CU gates by adjusting the inherent single-qubit operations, offering advantages over conventional fixed causal-order methods in terms of reduced circuit complexity and improved experimental flexibility. Furthermore, we develop an optical construction to implement the polarization CU gate using a stable and reciprocal Sagnac interferometer. Our work establishes a practical framework for scalable distributed quantum computation with flexible operations.
format Preprint
id arxiv_https___arxiv_org_abs_2603_08073
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Practical implementation of arbitrary nonlocal controlled-unitary gate via indefinite causal order
Liu, Wen-Qiang
Zheng, Zi-Han
Yin, Zhang-Qi
Wei, Hai-Rui
Quantum Physics
Quantum gate teleportation enables the implementation of nonlocal quantum operations without direct interactions between distant nodes. We propose an efficient protocol for implementing arbitrary controlled-unitary (CU) gates acting on two spatially separated parties via indefinite causal order (ICO). By establishing a maximally entanglement between two remote nodes and coherently superposing orders of single-qubit gates, our protocol circumvents the drawback of complex local two-qubit operations. This ICO-based approach enables full programmability of CU gates by adjusting the inherent single-qubit operations, offering advantages over conventional fixed causal-order methods in terms of reduced circuit complexity and improved experimental flexibility. Furthermore, we develop an optical construction to implement the polarization CU gate using a stable and reciprocal Sagnac interferometer. Our work establishes a practical framework for scalable distributed quantum computation with flexible operations.
title Practical implementation of arbitrary nonlocal controlled-unitary gate via indefinite causal order
topic Quantum Physics
url https://arxiv.org/abs/2603.08073