Improved entanglement-based high-dimensional optical quantum computation with linear optics

• URL: http://arxiv.org/abs/2602.07971v1
• Date: Sun, 08 Feb 2026 13:48:18 GMT
• Title: Improved entanglement-based high-dimensional optical quantum computation with linear optics
• Abstract summary: We present a family of entanglement-based optical controlled-SWAP gates on $mathbbC2otimes mathbbCdotimes mathbbCd$.<n>With the hybrid encoding, we encode the control qubits and target qudits in photonic polarization and spatial degrees of freedom.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: Quantum gates are the essential block for quantum computer. High-dimensional quantum gates exhibit remarkable advantages over their two-dimensional counterparts for some quantum information processing tasks. Here we present a family of entanglement-based optical controlled-SWAP gates on $\mathbb{C}^{2}\otimes \mathbb{C}^{d}\otimes \mathbb{C}^{d}$. With the hybrid encoding, we encode the control qubits and target qudits in photonic polarization and spatial degrees of freedom, respectively. The circuit is constructed using only $(2+3d)$ ($d\geq 2$) linear optics, beating an earlier result of 14 linear optics with $d=2$. The circuit depth 5 is much lower than an earlier result of 11 with $d=2$. Besides, the fidelity of the presented circuit can reach 99.4\%, and it is higher than the previous counterpart with $d=2$. Our scheme are constructed in a deterministic way without any borrowed ancillary photons or measurement-induced nonlinearities. Moreover, our approach allows $d>2$.

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