All the advantages of quantum multiplexing

Quantum technologies will profoundly improve the approach to several problems in a variaty of fields, leading to faster computation, more secure communication between remote parties and more precise measurements. The future development of such technologies, however, is jeopardized by several erros that might occur in a real implementation. Device imperfections and losses in the channel, in fact, are very detrimental for the performance of such systems. Therefore they must strongly rely on efficient methods to detect and correct those errors. To address this goal, several quantum error correction codes (QECCs) and purification methods have been developed in the last few decades. However, an efficient realization of such QECCs is still far from being reached due to the enormous number of physical resources required. In a recent work the authors have shown that the technique of quantum multiplexing (QM) allows to reduce the number of quantum memories required in a purification protocol and in a simple error correction scheme. Here, we apply this technique to the redundancy QECC, the quantum Reed-Solomon code and the surface code in a quantum communication scenario, in which the channel loss is the main source of error. We show that for such codes, QM allows to reduce drastically the number of photons, qubits and two-qubit gates required for their encoding while maintaining the same performance of the traditional approach. We describe a possible realization of QM that is based on exploiting multiple degrees of freedom of a single photon (for instance time-bin and polarization) by using optical elements, such as beam splitters and optical switches. We also show a realistic implementation of QM using the state-of-the-art devices under a practical scenario. We believe that QM is a valid approach to make quantum technologies more feasible in the near future.