Diamond quantum repeator for blind quantum computing

Wei Li, Ronghua Shi, Ying Guo

Pieter-Jan Stas, Yan-Cheng Wei, Aziza Suleymanzade +12 more

We show progress towards the experimental demonstration of distributed blind quantum computing using a two node quantum network of Silicon-Vacancy (SiV) centres in diamond nanocavities.

Joseph F. Fitzsimons, Elham Kashefi

Yan-Cheng Wei, Pieter-Jan Stas, Aziza Suleymanzade +16 more

Blind quantum computing is a promising application of distributed quantum systems, in which a client can perform computations on a remote server without revealing any details of the applied circuit. Although the most promising realizations of quantum computers are based on various matter-qubit platforms, implementing blind quantum computing on matter qubits remains a challenge. Using silicon-vacancy (SiV) centers in nanophotonic diamond cavities with an efficient optical interface, we demonstrated a universal quantum gate set consisting of single- and two-qubit blind gates over a distributed two-node network. Using these ingredients, we performed a distributed algorithm with blind operations across our two-node network, proving a route to develop blind quantum computation with matter qubits in distributed, modular architectures.

Hideo Kosaka

Min Xiao, Yannan Zhang

In blind quantum computation (BQC), a client with weak quantum computation capabilities is allowed to delegate its quantum computation tasks to a server with powerful quantum computation capabilities, and the inputs, algorithms and outputs of the quantum computation are confidential to the server. Verifiability refers to the ability of the client to verify with a certain probability whether the server has executed the protocol correctly and can be realized by introducing trap qubits into the computation graph state to detect server deception. The existing verifiable universal BQC protocols are analyzed and compared in detail. The XTH protocol (proposed by Xu Q S, Tan X Q, Huang R in 2020), a recent improvement protocol of verifiable universal BQC, uses a sandglass-like graph state to further decrease resource expenditure and enhance verification capability. However, the XTH protocol has two shortcomings: limitations in the coloring scheme and a high probability of accepting an incorrect computation result. In this paper, we present an improved version of the XTH protocol, which revises the limitations of the original coloring scheme and further improves the verification ability. The analysis demonstrates that the resource expenditure is the same as for the XTH protocol, while the probability of accepting the wrong computation result is reduced from the original minimum (0.866) d* to (0.819) d*, where d* is the number of repeated executions of the protocol.