2d Fourier spectroscopy of disordered quantum wells

Abstract

We consider the problem of coherent coupling between spatially separated exciton states in disordered quantum wells (QW) from the perspective of two‐dimensional (2d) Fourier spectroscopy, which is sensitive to interaction between excitations. We present the basic theory of spectroscopy of QW that demonstrate split exciton resonances in linear spectra, which is characteristic for long interfacial inhomogeneities.We find that the coherent coupling is governed by the relation between the disorder correlation length rc and the characteristic length of Coulomb correlations RI. If rc ≫ RI the coherent coupling is absent and 2d spectra are simply elongated along the diagonal (inhomogeneously broadened). In the opposite limit coupling exists and manifests itself in the form of respective off‐diagonal peaks in 2d spectra (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Coherent coupling between exciton resonances governed by the disorder potential

“…In order to interpret the measured 2D spectra, we perform calculations based on microscopic theory of semiconductor coherent nonlinear response in QWs with in-plane inhomogeneous disorder potentials. 38,39 Coherent semiconductor excitations are described by exciton operators…”

“…In Ref. 39, a simple case was considered when the main effect is due to the spatial extent of β. Expanding Eq.…”

Quantum Field Theory of Exciton Correlations and Entanglement in Semiconductor Structures

“…For example, the specific form of the exciton states has not been used for the derivation of main formulas and therefore the same arguments can be repeated for excitons in arbitrary confinement potential. This allows using this approach for description of nonlinear optical response of disordered quantum wells (Erementchouk et al, 2011).…”