Fault tolerant deterministic quantum communications using GHZ states over collective-noise channels

Abstract

This study proposes two new coding functions for a GHZ state and a GHZ-like state, respectively. Based on these coding functions, two fault tolerant deterministic quantum communication (DQC) protocols are proposed. Each of the new DQC's is robust under one kind of collective noises: collective-dephasing noise and collective-rotation noise, respectively. The sender can use the proposed coding functions to encode his/her message, and the receiver can perform the Bell measurement to obtain the sender's message. In comparison to the existing fault tolerant DQC protocols over collective-noise channels, the proposed protocols provide the best qubit efficiency. Moreover, the proposed protocols are also free from the ordinary eavesdropping and the information leakage.