No-cloning theorem, a profound fundamental principle of quantum mechanics, also provides a crucial practical basis for secure quantum communication. The security of communication can be ultimately guaranteed if the output fidelity via the communication channel is above the no-cloning bound (NCB). In quantum communications using continuous-variable (CV) systems, Gaussian states, more specifically, coherent states have been widely studied as inputs, but less is known for non-Gaussian states. We aim at exploring quantum communication covering CV states comprehensively with distinct sets of unknown states properly defined. Our main results here are (i) to establish the NCB for a broad class of quantum non-Gaussian states, including Fock states, their superpositions, and Schrodinger-cat states and (ii) to examine the relation between NCB and quantum non-Gaussianity (QNG). We find that NCB typically decreases with QNG. Remarkably, this does not mean that QNG states are less demanding for secure communication. By extending our study to mixed-state inputs, we demonstrate that QNG specifically in terms of Wigner negativity requires more resources to achieve output fidelity above NCB in CV teleportation. The more non-Gaussian, the harder to achieve secure communication, which can have crucial implications for CV quantum communications.

无克隆定理是量子力学的深刻基本原理，也为安全的量子通信提供了至关重要的实践基础。如果通过通信通道的输出保真度高于无克隆限制（NCB），则可以最终确保通信的安全性。在使用连续变量（CV）系统的量子通信中，高斯态，更具体地说，相干态作为输入已被广泛研究，但对于非高斯态却知之甚少。我们的目标是全面探索涵盖CV状态的量子通信，并正确定义不同的未知状态集。我们在这里的主要结果是（i）为广泛的一类量子非高斯态建立NCB，包括福克态，它们的叠加，Schrodinger-cat状态和（ii）研究NCB与量子非高斯（QNG）之间的关系。我们发现NCB通常随着QNG的减少而降低。值得注意的是，这并不意味着QNG状态对安全通信的要求降低。通过将我们的研究扩展到混合状态输入，我们证明了QNG（特别是在维格纳负性方面）需要更多的资源来实现CV隐形传态中高于NCB的输出保真度。非高斯越多，实现安全通信的难度就越大，这可能对CV量子通信产生至关重要的影响。我们证明，就维格纳负性而言，QNG特别需要维格纳负值，以便在CV隐形传态中获得高于NCB的输出保真度。非高斯越多，实现安全通信的难度就越大，这可能会对CV量子通信产生至关重要的影响。我们证明，就维格纳负性而言，QNG特别需要维格纳负值，以便在CV隐形传态中获得高于NCB的输出保真度。非高斯越多，实现安全通信的难度就越大，这可能对CV量子通信产生至关重要的影响。