Complete hyperentangled-Bell-state analysis for photon systems assisted by quantum-dot spins in optical microcavities

Abstract

Bell-state analysis (BSA) is essential in quantum communication, but it is impossible to distinguish unambiguously the four Bell states in the polarization degree of freedom (DOF) of two-photon systems with only linear optical elements, except for the case in which the BSA is assisted with hyperentangled states, the simultaneous entanglement in more than one DOF. Here, we propose a scheme to distinguish completely the 16 hyperentangled Bell states in both the polarization and the spatial-mode DOFs of two-photon systems, by using the giant nonlinear optics in quantum dot-cavity systems. This scheme can be applied to increase the channel capacity of long-distance quantum communication based on hyperentanglement, such as entanglement swapping, teleportation, and superdense coding. We use hyperentanglement swapping as an example to show the application of this HBSA.

Complete hyperentangled Bell state analysis for polarization and time-bin hyperentanglement

“…Otherwise, setups with more nonlinearities need to be prepared in advance for all possible situations. Second, in our scheme the discrimination of the second DOF is realized without any nonlinear optics while in other schemes the analysis of both DOFs resorts to nonlinearities [44,46]. These two advantages make our scheme time-saving and resourcesaving and thus more useful and practical.…”

“…It has been shown that 16 hyperentangled Bell states can be classed into only 7 groups with linear optics [40,41]. Therefore, auxiliary states and assistant tools have to be utilized to accomplish complete state analysis [42][43][44][45][46][47]. In 2010, Sheng et al proposed the first complete HBSA scheme for polarization and spatial-mode hyperentangled states [44].…”

Efficient single-photon-assisted entanglement concentration for an arbitrary entangled photon pair with the diamond nitrogen-vacancy center insides cavity

“…Based on single electron spin confined in a charged quantum dot inside a microcavity, Hu et al [70] present a scheme to generate photon polarization entanglement. Ren et al [71] proposed a scheme for completing hyperentangled-Bell-state analysis for photon systems. Based on diamond NV centers inside photonic crystal cavities, Ren et al [38] proposed a protocol to implement the hyperentanglement purification of two-photon systems in nonlocal hyperentangled Bell states.…”

Hyperentanglement concentration for time-bin and polarization hyperentangled photons

“…Hyperentangled states can be used to beat the channel capacity limit of superdense coding with linear optics [23,24], construct hyper-parallel photonic quantum computing [25,26] which can reduces the operation time and the resources consumed in quantum information processing, achieve the high-capacity quantum communication with the complete teleportation and entanglement swapping in two DOFs [27,28]. They can also help to design deterministic entanglement purification protocols [29][30][31][32] which work in a deterministic way, not a probabilistic one, far different from conventional entanglement purifi- * Email address: xihanlicqu@gmail.com cation protocols [33][34][35].…”