Superdense Coding

Yousheng Zhou, Feng Wang, Ming-Xing Luo

Lewis Westfall, Avery M. Leider

Heinz, Benjamin

Superdense coding is a quantum communication protocol that enables the transmission of more than one classical bit of information per qubit, using entangled states. While superdense coding with 2-qubits is well understood and directly maps to the Bell states, the same cannot be said for higher numbers of qubits. This project aims to develop an algorithm for superdense coding using a larger number of qubits, while analyzing how the capacity for information transmission scales with qubit count. Additionally, we will determine the error thresholds for accurately reconstructing the encoded information and investigate how error scales as the number of qubits increases. Gaining a deeper understanding of superdense coding has significant applications in quantum cryptography, as superdense coding schemes can be used to set up quantum secure direct communication (QSDC) protocols.

Wei Yang, Liusheng Huang, An Liu +2 more

Quantum superdense coding (QSC) is an interesting application of quantum communications. It exploits the special property of quantum entanglement to perform classical communications and results in a spectacular result. In this paper, the density of QSC problem is investigated and a time synchronization mechanism is shown to be helpful for improving the coding efficiency. A new quantum–classical hybrid QSC scheme based on a time synchronization mechanism is proposed. The scheme is extended to the case in which any number of qubits (and further qudits) are involved. A desirable coding efficiency, which is shown to converge to log2(d + 1) (where d denotes the dimension of the quantum system employed) in the generalized case, is deduced for this time-assisted superdense coding.

Z. Shadman, Hermann Kampermann, Dagmar Bruß +1 more

We study the superdense coding capacity in the presence of quantum channels with correlated noise. We investigate both the cases of unitary and nonunitary encoding. Pauli channels for arbitrary dimensions are treated explicitly. The superdense coding capacity for some special channels and resource states is derived for unitary encoding. We also provide an example of a memory channel where nonunitary encoding leads to an improvement in the superdense coding capacity.