Quantum key distribution with single-particle and Bell state

A quantum key distribution protocol with single-particle and Bell state is proposed, in which one player Alice sends the states from some special single-particles and Bell states, the other player Bob measures these states in the single-particle basis or Bell basis, and then establish their secret key. Through combining the single-particle and Bell state novelly, the error rate of eavesdropping in our protocol can be increased up to 3/8. Compared to BB84, our protocol can get higher secure key rate in practice.