Holographic Schwinger effect in a confining D3-brane background with   chemical potential
  Using the AdS/CFT correspondence, we investigate the Schwinger effect in a confining D3-brane background with chemical potential. The potential between a test particle pair on the D3-brane in an external electric field is obtained. The critical field $E_c$ in this case is calculated. Also, we apply numerical method to evaluate the production rate for various cases. The results imply that the presence of chemical potential tends to suppress the pair production effect. 
Zi-qiang Zhang, De-fu Hou, Yan Wu and Gang Chen
hep-ph