Robust quantum dialogue based on the measurement correlation of three-qubit entangled states over collective noise channels
Abstract
In this paper, two robust quantum dialogue (QD) protocols over collective-dephasing noise channel and collective- rotation noise channel are proposed, respectively, by using three-qubit entangled states as the initial quantum resource. Alice generates a series of three-qubit entangled states and divides them into a physical qubit sequence and a logical qubit sequence. Then, Alice sends the logical qubit sequence to Bob. Afterward, Alice and Bob measure the physical qubit sequence and the logical qubit sequence, respectively. According to his measurement result, Bob generates a new logical qubit sequence with no measurement performed. Then, Bob encodes his secret messages on the new logical qubit sequence by performing logical unitary operations on it. Afterward, Bob sends the encoded logical qubit sequence back to Alice. Finally, Alice encodes her secret messages on the encoded logical qubit sequence from Bob by performing logical unitary operations on it and publishes her measurement. As a result, Alice and Bob can decode out each other's secret messages. By virtue of the measurement correlation of three-qubit entangled states, two participants share the initial states of message logical qubits privately. In this way, the information leakage problem is overcome. The proposed protocols only need the single-photon measurements. Compared with previous QD protocols workable over collective noise channels, the proposed protocols have the highest information-theoretical efficiency.
