强场QED下的Schwinger效应

12月1-2号访问了中国科技大学交叉学科理论研究中心，并做了一个报告

“Schwinger effect of QED in strong fields ”

对此感兴趣者可以参看http://icts.ustc.edu.cn/chinese/

或者http://icts.ustc.edu.cn/chinese/seminar/transparencies/Bai-Song%20Xie/Bai-Song111201.html

1951年Schwinger在Physical Review 发表著名论文Schwinger, On gauge invariance and vacuum polarization, PR82, 664(1951).

Schwinger临界场强对应的激光强度10^29W/cm^2,目前激光强度10^22至10^23 W/cm^2。但随着欧洲ELI计划10^25 W/cm^2的即将实现，很多QED效应将得到实验检验与验证，强场物理将迎来理论研究的新的热潮。Schwinger擅长微分处理，Feynman则擅长积分处理，因创立QED与朝永振一郎获1965年Nobel物理奖。

   最近加拿大和俄罗斯人Gordon W. Semenoff

Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, Canada V6T 1Z1；Konstantin Zarembo Nordita, Roslagstullsbacken 23, SE-106 91 Stockholm, Sweden and ITEP, Moscow, Russia

的一篇PRL文章Holographic Schwinger Effect

非常有意思：G. W. Semenoff and K.Zarembo, PRL107, 171601 (2011)

用AdS/CFT全息性推广了Schwinger著名的对产生率的指数型抑制的公式（类似量子力学中外场下电子的Landau隧穿电离）得到了这样的结论：存在较高的临界场,当场高于它时使得指数抑制不再。以下是该文的摘要

We study tunneling pair creation of W bosons by an external electric field on the Coulomb branch of N=4 supersymmetric Yang-Mills theory. We use AdS/CFT holography to find a generalization of Schwinger’s formula for the pair production rate to the strong coupling, planar limit which includes the exchange of virtual massless particles to all orders. We find that the pair creation formula has an upper critical electric field beyond which the process is no longer exponentially suppressed. The value of the critical field is identical to that which occurs in the Born-Infeld action of probe D3-branes in the AdS5XS5 background, where AdS5 and S5 are 5-dimensional anti–de Sitter space and the 5-sphere, respectively.