Research On Properties Of Light States Before And After The Operation Of Delocalized Photon Addition

Quantum entanglement is an important resource in the field of quantum technology such as quantum computing,quantum communication and quantum precision measurement.In order to better handle quantum information tasks,it is technically necessary to prepare some strange entangled quantum states or improve the entanglement degree of quantum states.Quantum states are divided into Gaussian states and non-Gaussian states.Gaussian states have the advantages of simple operation and simple description,but also have their limitations;Although the non-Gaussian state is more difficult to prepare experimentally and is usually characterized by higher-order correlation,many quantum technologies need to use the non-Gaussian entangled state.There are many schemes to prepare non-Gaussian entangled states.For example,using linear optical network devices,input different light fields and cooperate with appropriate measurement,non-Gaussian entangled states can be prepared.Theoretically,non-Gaussian entangled states can be generated by applying different input light fields through some delocalized operations(referring to the operation of superposition of multiple local operations).In this paper,several interesting nonGaussian entangled states are prepared by using the delocalized photon addition operation.The paper mainly consists of the following four parts:First of all,using the delocalized single-photon addition operator a1?+eiφa2?(which is the superposition phase)to act on two independent coherent states,a twomode non-Gaussian entangled coherent state is obtained.We analyze the entanglement properties of input and output states,give some results of statistical properties,and show the properties of their Wigner functions.It is found that the non-classical property of this state is obviously affected by the superposition phase.Secondly,the corresponding non-Gaussian entangled states are obtained by applying a1?+eiφa2?,respectively,to two independent hot states,two independent singlemode squeezed vacuum states,and two-mode squeezed vacuum states.We study the non-classical properties such as entanglement and make a comparative analysis.The results show that the delocalization operation can produce or improve entanglement,but the non-classical properties of these states are not significantly affected by the superposition phase.Thirdly,we use the delocalized multi-photon addition operator of a1?m+eiφa2?m and(a1?+eiφa2?)m to act on two independent coherent states and obtain a series of two-mode non-Gaussian quantum states.We find that the states produced by a1?m+eiφa2?m and(a1?+eiφa2?)m have better performance in some properties.Finally,we use a1?+eiφa2?,eiφa3?,to act on three independent coherent states,and obtain the three-mode non-Gaussian entangled coherent states.Using some criteria and standards,we study some non-Gaussian statistical properties of the state.The results show that the output state has the properties of non-Gaussian entanglement and some non-classical properties.In a word,we have prepared some non-Gaussian entangled quantum states,and studied their properties and the changes of their physical parameters.The research of these problems provides available resources for quantum technology and theoretical reference for experimental design.