Electric field induced narrowing of exciton line width

TL;DR

This paper investigates how electric fields influence the exciton absorption line width in quantum wells, revealing that moderate fields can cause spectral line narrowing due to modifications in inhomogeneous broadening.

Contribution

It demonstrates that electric fields can induce narrowing of exciton spectral lines by altering inhomogeneous broadening mechanisms, a novel insight into exciton behavior under electric fields.

Findings

Electric fields can decrease inhomogeneous broadening in quantum wells.

Counterintuitive spectral line narrowing can occur under certain conditions.

The effect depends on well thickness and disorder characteristics.

Abstract

Considering effects of electric field on the low temperature absorption line of quantum well excitons, we show that, for moderate strength of the electric field, the main contribution to the field dependence of the line-width results from field induced modifications of inhomogeneous broadening of excitons. We find that the strength of the random potential acting on quantum well excitons due to alloy disorder and interface roughness can either decrease or increase with field depending upon the thickness of the well. This means that under certain conditions one can observe counterintuitive narrowing of exciton spectral lines in electric field.