Recurrent generation of maximally entangled single particle states via quantum walks on cyclic graphs

Abstract

Maximally entangled single-particle states (MESPS) are opening new possibilities in quantum technology as they have the potential to encode more information and are robust to decoherence compared to their nonlocal two-particle counterparts. We find that a single coin can generate MESPS at recurrent time steps (periodically) via discrete-time quantum walks on both $4$ and $8$ site cyclic graphs. This scheme is resource-saving with possibly the most straightforward experimental realization since the same coin is applied at each time step. We also show that recurrent MESPS can be generated on any arbitrary $k$ site cyclic graph, $k\in \{3,4,5,8\}$ via effective-single (Identity and arbitrary coin) or two coin evolution sequences. Beyond their use in fundamental research, we propose an application of the generated MESPS in quantum cryptography protocols. MESPS as cryptographic keys can strengthen quantum-secure communication.

18 pages, 9 figures, 2 tables, accepted for publication in Phys. Rev. A (Letters)

References in corpus (4)

• Quantum state revivals in quantum walks on cycles
• Quantum direct communication protocol using recurrence in k-cycle quantum walk
• Maximal coin-position entanglement generation in a quantum walk for the third step and beyond regardless of the initial state
• Maximal coin-walker entanglement in a ballistic quantum walk

Cited by in corpus (5)

• Efficient implementation of discrete-time quantum walks on quantum computers
• Designing three-way entangled and nonlocal two-way entangled single particle states via alternate quantum walks
• Quantum cryptographic protocols with dual messaging system via 2D alternate quantum walk of a genuine single-photon entangled state
• Phase vs coin vs position disorder as a probe for the resilience and revival of single particle entanglement in cyclic quantum walks
• Controlling quantum chaos via Parrondo strategies on noisy intermediate-scale quantum hardware