Suppression of absorption by quantum interference in intersubband transitions of tunnel-coupled double quantum wells

TL;DR

This paper presents a scheme using asymmetric coupled quantum wells to suppress probe absorption via quantum interference, achieving broader transparency windows and complete elimination of absorption under certain conditions, advancing solid-state EIT applications.

Contribution

The work introduces a novel scheme for EIT in solids using CQWs, demonstrating broader transparency windows and complete absorption suppression without strict detuning requirements.

Findings

Probe absorption can be fully eliminated at Raman resonance.

The transparency window is significantly broader than in three-level systems.

Complete suppression of absorption is achievable without precise two-photon detuning.

Abstract

We propose and analyze an efficient scheme for suppressing the absorption of a weak probe field based on intersubband transitions in a four-level asymmetric coupled-quantum well (CQW) driven coherently by a probe laser field and a control laser field. By using the numerical simulation, we find that the magnitude of the transient absorption of the probe field is smaller than the three-level system based on the electromagnetically induced transparency (EIT) at line center of the probe transition, moreover, comparing with the scheme in three-level asymmetric double QW system, the transparency hole of the present work is much broader. By analyzing the steady-state process analytically and numerically, our results show that the probe absorption can be completely eliminated under the condition of Raman resonance (i.e. two-photon detuning is zero). Besides, we can observe one transparency window without requiring one- or two-photon detuning exactly vanish. This investigation may provide the possible scheme for EIT in solids by using CQW.