Nonlinear optical properties and Kerr nonlinearity of Rydberg excitons in Cu$_2$O quantum wells

TL;DR

This paper presents a theoretical study of the nonlinear optical properties of Rydberg excitons in Cu$_2$O quantum wells, focusing on Kerr nonlinearity, Rydberg blockade, and their spectral signatures.

Contribution

It provides analytical expressions and numerical analysis of linear and nonlinear optical responses of Rydberg excitons in quantum wells, including Kerr effects and Rydberg blockade phenomena.

Findings

Quantum well confinement states can be observed in optical spectra.

Kerr nonlinearity and self-phase modulation are significant in these systems.

Rydberg blockade leads to optical bleaching effects.

Abstract

The quantum confiment of Rydberg excitons (REs) in quantum structures opens the way towards considering nonlinear interactions in such systems. We present a theoretical calculation of optical functions in the case of a nonlinear coupling between REs in a quantum well with an electromagnetic wave. Using the Real Density Matrix Approach (RDMA), the analytical expressions for a linear and nonlinear absorption are derived and numerical calculations for Cu$_2$0 quantum wells are performed. The results indicate the conditions in which quantum well confinement states can be observed in linear and nonlinear optical spectra. The Kerr nonlinearity and self-phase modulation in such a system are studied. The effect of Rydberg blockade and the associated optical bleaching are also discussed and confronted with available experimental data.