Quantum state transfer and distribution of past–future correlations in a quantum network

We propose schemes for transmitting quantum states between spatially separated qubits in a quantum network by utilizing the inherent quantum fluctuations present in the background. These fluctuations have responses on the operations performed on the coupled qubits, enabling us to exploit them for accomplishing state transfer. Unlike traditional methods that rely on simultaneous correlations of qubits in the sending and receiving nodes, our approach leverages the past–future correlation between these qubits. It is important to note that the strength of the past–future correlation depends on the time difference between when the qubits begin their evolution with the fluctuations, and there exists a characteristic time beyond which the past–future correlation becomes negligible. The implementation of our transfer scheme overcomes the limitations of traditional quantum communication methods that heavily rely on the survival of simultaneous correlations.