Schwinger Effect and Negative Differential Conductivity in Holographic Models

Understand

The consequences of the Schwinger effect for conductivity is computed for strong coupling systems using holography.

• The one loop diagram on the flavor brane introduces an $O({\lambda \over N_c})$ imaginary part in the effective action for a Maxwell flavor gauge field.
• This in turn introduces a real conductivity in an otherwise insulating phase of the boundary theory.
• Moreover in certain regions of parameter space the differential conductivity is negative.