It is striking that the quantum Zeno effect can be used to launch a direct counterfactual communication between two spatially separated parties, Alice and Bob. So far, existing protocols of this type only provide a de...It is striking that the quantum Zeno effect can be used to launch a direct counterfactual communication between two spatially separated parties, Alice and Bob. So far, existing protocols of this type only provide a deterministic counterfactual communication service. However, this counterfactuality should be payed at a price. Firstly, the transmission time is much longer than a classical transmission costs. Secondly, the chained-cycle structure makes them more sensitive to channel noises. Here, we extend the idea of counterfactual communication, and present a probabilistic-counterfactual quantum communication protocol, which is proved to have advantages over the deterministic ones. Moreover, the presented protocol could evolve to a deterministic one solely by adjusting the parameters of the beam splitters.展开更多
This work proposes two fault tolerant quantum secure direct communication （QSDC） protocols which are robust against two kinds of collective noises： the collective-dephasing noises and the collective-rotation noises...This work proposes two fault tolerant quantum secure direct communication （QSDC） protocols which are robust against two kinds of collective noises： the collective-dephasing noises and the collective-rotation noises, respectively. The two QSDC protocols are constructed from four-qubit DF states which consist of two logical qubits. The receiver simply performs two Bell state measurements （rather than four-qubit joint measurements） to obtain the secret message. The protocols have qubit efficiency twice that of the other corresponding fault tolerant QSDC protocols. Furthermore, the proposed protocols are free from Trojan horse attacks.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61300203)
文摘It is striking that the quantum Zeno effect can be used to launch a direct counterfactual communication between two spatially separated parties, Alice and Bob. So far, existing protocols of this type only provide a deterministic counterfactual communication service. However, this counterfactuality should be payed at a price. Firstly, the transmission time is much longer than a classical transmission costs. Secondly, the chained-cycle structure makes them more sensitive to channel noises. Here, we extend the idea of counterfactual communication, and present a probabilistic-counterfactual quantum communication protocol, which is proved to have advantages over the deterministic ones. Moreover, the presented protocol could evolve to a deterministic one solely by adjusting the parameters of the beam splitters.
基金supported by the National Science Council, Taiwan, China (Grant No. NSC98-2221-E-006-097-MY3)
文摘This work proposes two fault tolerant quantum secure direct communication （QSDC） protocols which are robust against two kinds of collective noises： the collective-dephasing noises and the collective-rotation noises, respectively. The two QSDC protocols are constructed from four-qubit DF states which consist of two logical qubits. The receiver simply performs two Bell state measurements （rather than four-qubit joint measurements） to obtain the secret message. The protocols have qubit efficiency twice that of the other corresponding fault tolerant QSDC protocols. Furthermore, the proposed protocols are free from Trojan horse attacks.
