非平衡基的连续变量量子密码方案

在非平衡基下，通过局域操作引入纠缠态的非对称性，证明了非平衡基可以提高连续变量量子密码方案的密钥生成速率.以典型的密钥分配实验为例，经过数值计算验证，在同等密钥生成速率的条件下，非平衡基的量子密钥分配安全距离可以扩展20 km左右.

Research on Continuous Variable Quantum Cryptography with Unbalanced Basis Choice

With its security based on quantum no-cloning and Heisenberg uncertainty relation, the quan-tum cryptography is a newly developed key distribution protocol. The recent research on continuous varia-ble quantum cryptography assumes that the choice of basis is balanced. However, the performance of continuous variable quantum cryptography is an interesting but open question. By introducing the asym-metry in the shared bipartite two-mode entanglement state, the secret key rate was improved with unbal-anced basis. Furthermore, numerical simulations with typical continuous variable quantum key distribu-tion experiment show that the secure distance can be prolonged by 20km for a given secure key rate.