Multipartite quantum entanglement creation for distant stationary systems

Abstract

We present efficient protocols for creating multipartite Greenberger-Horne-Zeilinger (GHZ) and W states of distant stationary qubits. The system nonuniformity and/or the non-ideal single-photon scattering usually limit the performance of entanglement creation, and result in the decrease of the fidelity and the efficiency in practical quantum information processing. By using linear optical elements, errors caused by the system nonuniformity and non-ideal photon scattering can be converted into heralded loss in our protocols. Thus, the fidelity of generated multipartite entangled states keeps unchanged and only the efficiency decreases. The GHZ state of distant stationary qubits is created in a parallel way that its generation efficiency considerably increases. In the protocol for creating the W state of N distant stationary qubits, an input single photon is prepared in a superposition state and sent into N paths parallelly. We use the two-spatial-mode interferences to eliminate the “which path” single-photon scattering “knowledge”. As a result, the efficiency of creating the N-qubit W state is independent of the number of stationary qubits rather than exponentially decreases.

Phononic-waveguide-assisted steady-state entanglement of silicon-vacancy centers

“…Multiparticle entanglement has attracted great attention for its diverse applications in quantum metrology and quantum computing [1][2][3][4][5][6][7][8][9][10]. Efforts along this direction have lead to a plenty of proposals for generating entangled states with particles as many as possible [11][12][13], such as spin squeezing states [14][15][16] and GHZ states [17][18][19][20]. So far, multiparticle entanglement has been realized involving up to 20 qubits in trapped-ion systems [21], and 12 qubits in superconducting circuits [22].…”

Deterministic Conversion of Hyperentangled States with Error‐Heralded Quantum Units

“…Quantum entanglement [1,2] depending on quantum mechanics plays an indispensable role in various quantum information technologies (QITs) and causes efficacious applications that tremendously transcend their respective classical counterparts. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] In particular, nonlocal quantum entanglement between distant nodes is available for large-scale useful quantum communication, [19][20][21][22][23][24] distributed quantum computation, [25] and state analysis. [26,27] The common quantum entangled states include Bell state, Greenberger-Horne-Zeilinger (GHZ) state, [28] W state, [29] and Knill-Laflamme-Milburn (KLM) state.…”

Self-error-rejecting multipartite entanglement purification for electron systems assisted by quantum-dot spins in optical microcavities

“…Multipartite entangled systems [23][24][25][26] shared by the detached parties in remote locations are in a maximally entangled state for the security and the efficiency of quantum communication. However, in a practical transmission, the multipartite propagated away from each other are bound to sustain channel noises, which will inevitably degrade the entanglement or even make the maximally entangled state change into a mixed one, making quantum communication insecure.…”