| Quantum communication technology,based on quantum superposition states and quantum entanglement effects,realizes the effective transmission of information,with advantages such as high transmission rate and high confidentiality.It is of great significance for national information security,military,finance and other fields.However,when the quantum optical signal is transmitted in free space and in the sea,it will inevitably be affected by various suspended particles in the environment,which will lead to a decline in communication quality.Therefore,in this study,microbial particles,coastal polluted atmospheric aerosols,and marine non-pigmented agglomerated particles are selected as the influencing factors.Combined with the changes of quantum states in noisy channels,the effects of three kinds of particles on the performance of quantum communication are studied,providing theoretical references for the stable and high-quality transmission of quantum optical signals in different environments.The specific work is as follows:1.In order to study the influence of microbial particles on the performance of quantum channels,the extinction characteristics of microbial particles are analyzed based on Mie scattering theory.According to the spectral distribution function and extinction coefficient of particles,relationships between the transmission distance,number concentration of microbial particles and link attenuation,channel capacity,survival function,as well as quantum bit error rate are established for bit flip noise channel and depolarization noise channel,and the simulation experiments are carried out.The results show that as the concentration of microbial particles increases,the link attenuation and quantum error rate increase,while the channel capacity and survival function decrease.In microbial environments,compared to depolarization noise,bit flip noise has a more significant impact on quantum states.2.In order to study the influence of polluted aerosol particles over coastal air on the characteristics of quantum channels,based on Mie scattering theory,combined with the influence of air humidity on aerosol particle size and complex refractive index,the extinction coefficient of polluted aerosol over coastal water is calculated.According to the spectral distribution function of aerosol particles,relationships between the transmission distance,number concentration of aerosol particles and link attenuation,link efficiency,as well as quantum entanglement degree are established.The changes of fidelity of quantum teleportation based on partial memory channel are studied for the bit flip noise channel,the depolarization noise channel,and the xz dephasing noise channel.The results show that as the particle number concentration of polluted aerosol over coastal air increases,the link attenuation increases,while the link efficiency and quantum entanglement decrease.By introducing a partial memory channel,the fidelity of quantum teleportation under the influence of three types of noise has been significantly improved.3.In order to study the influence of marine non-pigmented agglomerated particles on underwater quantum communication performance,the scattering and absorption characteristics of marine non-pigmented agglomerated particles are analyzed based on Gordon model.For optical signals of different wavelengths,relationships between the mass concentration of marine non-pigmented agglomerated particles and link attenuation,channel establishment rate,amplitude damping channel capacity,as well as quantum security key generation rate are established and simulated.The results show that with the increase of the mass concentration of non-pigment agglomerated particles in the ocean,the link attenuation shows an upward trend,while the channel establishment rate,amplitude damping channel capacity,and quantum security key generation rate show a downward trend. |
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