• Acta Photonica Sinica
  • Vol. 50, Issue 12, 1201006 (2021)
ZHANG Qinwei, LIU Xia*, CAO Lianzhen, YANG Yang, LI Yingde, and ZHAO Jiaqiang
Author Affiliations
  • Shandong Provincial Key Laboratory of Multi-photon Entanglement and Manipulation,Department of Physics and Optoelectronic Engineering, Weifang University, Weifang , Shandong 261061, China
  • show less
    DOI: 10.3788/gzxb20215012.1201006 Cite this Article
    Qinwei ZHANG, Xia LIU, Lianzhen CAO, Yang YANG, Yingde LI, Jiaqiang ZHAO. Entanglement Degradation of Photons Entangled States in Oceanic Turbulence[J]. Acta Photonica Sinica, 2021, 50(12): 1201006 Copy Citation Text show less

    Abstract

    Based on the theory of Kolmogorov oceanic turbulence spectrum and quantum optics, the theoretical model that the spatial two-qubit photons entangled states prepared by parametric down-converted propagate through the Kolmogorov oceanic turbulence is constructed. The theoretical expressions for entanglement degradation of the spatial two-qubit photons entangled states in oceanic turbulence are obtained. Then, using the Wootters's concurrence, the influence of Kolmogorov oceanic turbulence on the spatial two-qubit photons entangled states with numerical simulation is analyzed. The results show that the parameters of the laboratory device which are prepared the spatial two-qubit entangled states will make a great impact on the entanglement. And the smaller separation of two signal (idler) apertures or the separation between the two signal and the idler apertures is, the higher fidelity of the spatial two-qubit photon entangled states is. The entanglement of spatial two-qubit states can well maintain in the salinity-induced oceanic turbulence when the rate of dissipation of mean-square temperature is small and the rate of dissipation of turbulent kinetic energy per unit mass of fluid is big with numerical calculation. These results have important significance for long distance underwater quantum communication via quantum entangled channel.

    0 Introduction

    It is well known that Spontaneous Parametric Down-Conversion (SPDC) is an important way to produce entangled photons with various degrees of freedom, such as polarization, spatial, time and Orbital Angular Momentum (OAM) and so on1-6. As a main resource in quantum information processing, entangled photons have been applied in quantum teleportation7, quantum dense coding8, Quantum Imaging (GI)39 and quantum metrology10-11. Two-qubit states based on the position correlations of entangled photons are referred to as spatial two-qubit states12-16, which can be collected by position correlated detectors in linear optical system. This spatial two-qubit entangled states can also be used in quantum teleportation17, quantum secure direct communication18, quantum key distribution19 and the verification of quantum nonlocality20-21.

    Copy Citation Text
    Qinwei ZHANG, Xia LIU, Lianzhen CAO, Yang YANG, Yingde LI, Jiaqiang ZHAO. Entanglement Degradation of Photons Entangled States in Oceanic Turbulence[J]. Acta Photonica Sinica, 2021, 50(12): 1201006
    Download Citation