The Study About Phenomena Of Pairs Creation From Vacuum In Supercritical Field

The famous mass-energy equation E = mc2 is presented by Einstein in 1905,the equation reveals that it is possible that matter and energy are inter-changeable.The transformation from matter to energy has been realized since the development of the nuclear technology.But the transformation from energy to matter has not been authentically realized yet,however since the important physical meaning of the transformation from energy to matter,the relevant stud-ies have never stopped.On the other hand,in 1929 Dirac presented the Dirac equation,he pre-dicted that the vacuum is filled with electrons with negative energy to explain the existence of the negative energy electron state,the electrical property of the electrons with negative energy dose not show up because of the symmetry.This prediction provides a possibility for the transformation from matter to energy,the electron with negative energy in the vacuum could be excited to the positive energy electron state by supercritical field and left a hole in the negative energy electron state,so in effect,it could be considered as the excitation of a elec-tron and a positron(hole)from the vacuum by the supercritical field.In 1936,the premier relevant calculation was done by Schwinger which told us that the threshold value of the electric field intensity to create pairs from the vacuum was 1018V/m by using the quantum field theory,however the electric field intensity has not been realized yet,so the transformation from energy to matter has not been authentically realized.But the excitation of pairs with the participation of high energy electrons has been observed in experiment,so the researchers show great expectation and attention to the pure excitation of pairs by strong field.In recent years,since the development of the high energy laser technique,the most high laser intensity can be realized has been 1023W/cm2,it is foresee-able that the excitation of pairs from the vacuum by high energy laser which prove the transformation from energy to matter could be realized in the seeable future.So it seems more and more important to analyse the excitation of pairs from vacuum by the supercritical field theoretically to provide guidance and help for future experiments.In this paper,we analyse the physical phenomena during the excitation of pairs by supercritical field in the vacuum by using the computational quantum field theory method.The physical phenomena include the positron wave in-terference and Klein tunnel during the production of pairs in the double-well potential,the generated positrons concentrate to the positive momentum region in the double-well potential,and Klein tunneling phenomenon with pair creation process.We wish to provide some guidance and data for future experiments.In the first part(chapter 1,2),we would introduce the back ground of the pair creation and the development of the theory and experiment about pair cre-ation in chapter 1.Then chapter 2 we would introduce and analyse the computa-tional quantum field theory method.The main theory of this method is to solve the time-dependent Dirac equation to evolve the negative energy electron state in the supercritical field and then project to the positive energy electron state to obtain the number and distribution of the pairs created by the supercritical field from vacuum.At the last part of this chapter,we would introduce Klein tunneling phenomenon,which could be used in the next part of the paper.In the second part(chapter 3 to 5),we would introduce the concrete calcu-lation result about the pair creation and the conclusion we get.In the chapter 3,we introduce the phenomenon that the created positron waves interfere and the stationary wave emerges during the pair creation in the double well potential.Studies show that in the process of pair creation in the double well potential,the created positron waves would interfere and form the stationary wave if the the distance between the double wells satisfies standing wave condition.The wave interference would affect the pair creation process.Because of the Klein tun-neling,all of the stationary wave packages would disappear in the double well finally.In the chapter 4,we introduce the phenomenon that the created positron momentum centralizes in one direction during the pair creation in the double well potential.The distribution of the created positron momentum by the single well is symmetric in the momentum space,but the studies show that if the two wells are opened at different times,the distribution of the created positron mo-mentum would centralize in one direction.This phenomenon would provide a programme to generate more positrons which move in a single direction.In the chapter 5,we study the Klein tunneling phenomenon with electron-positron pair creation process.Pairs can be created from the vacuum by a supercritical single-well potential(for electrons).In the time region,the time-dependent growth pattern of the created pairs can be characterized by four distinct regimes which can be considered as four different statuses of the single well.We find that if positrons penetrate the single well by Klein tunneling in different statuses,the total number of the tunneling positrons will be different.If Klein tunneling be-gins at the initial stage of the first status i.e.when the sing well is empty,the tunneling process and the total number of tunneling positrons are similar to the traditional Klein tunneling case without considering the pair creation process.As the tunneling begins later,the total tunneling positron number increases.The number will finally settle to an asymptotic value when the tunneling begins later than the middle time of the second status.In the third part(chapter 6),we would give the summary and the outlook of my work.