超强激光序列诱导Dirac真空中正电子产生  

Induction of Positron Creation in Dirac Vacuum by Super Intense Laser Sequence

作　　者：任芝 尚大凯 路欣瑜 李松涛[1,2] 龚驰 Ren Zhi;Shang Dakai;Lu Xinyu;Li Songtao;Gong Chi(Department of Mathematics and Physics,North China Electric Power University,Baoding 071003,Hebei,China;Hebei Key Laboratory of Physics and Energy Technology,Baoding 071003,Hebei,China)

机构地区：[1]华北电力大学数理系,河北保定071003 [2]河北省物理学与能源技术重点实验室,河北保定071003

出　　处：《光学学报》2024年第20期277-284,共8页Acta Optica Sinica

基　　金：国家自然科学基金(12304337);中央高校基本科研经费(20226943)。

摘　　要：在多束超强激光形成的振荡阶梯势阱中,通过计算量子场论方法来计算真空中正电子产生。对于多束激光形成的静态阶梯势阱,发现当场强相同的次临界激光束被有效排列时,可以实现超临界势阱效应,提高能量利用率。对隧穿机制与光子吸收机制效应下的正电子产生进行探索,发现正电子产生速率在两种机制形成的动力学辅助效应下被进一步增强,这种次临界场强振荡阶梯势阱能够为未来实验中降低正电子产生阈值提供有价值的参考。Objective Dirac proposed the negative energy sea theory in 1931 and predicted the existence of positrons.He suggested that an electron removed from a filled negative energy state would leave a particle called an“antielectron”in its place,which we now know as the positron.It has the same mass as the electron but carries a positive charge.Currently,two mechanisms are recognized for generating positrons in a vacuum:the Schwinger tunneling mechanism and the multiphoton absorption mechanism.Traditionally,there have been at least two main methods for manipulating outfields to generate superior results.The first method involves generating a strong external field through the superposition of two Coulomb fields.The first method involves generating a strong external field through the superposition of two Coulomb fields.The second method explores the properties of the vacuum by using a very powerful laser to provide an excitation field.However,pure laser energy fields have not been observed to generate positrons from the vacuum in laboratory experiments,due to the insufficient laser intensity and photon energy required to produce observable positrons.Currently,it is not feasible to achieve electric field intensities at the critical value in the laboratory.Given this research status,our study arranges multiple subcritical laser beams in a specific sequence to create a supercritical step potential,thereby lowering the threshold for positron generation.The results show that increasing the number of steps significantly boosts positron production,with each step formed between two laser beams transmitted in the same direction.Methods In this study,we apply the computational quantum field theory(CQFT)method,based on the numerical solution of the timedependent Dirac equation,to study the positron generation process in a spatially and temporally varying laser field.This approach allows visualization of positron production dynamics and addresses conceptual issues related to negative energy states.In the process of energytomass co

关 键 词：量子光学 超强激光 正负电子对 Dirac真空 

分 类 号：O57[理学—粒子物理与原子核物理]