Quantum-correlated two-photon transitions to excitons in semiconductor quantum wells

TL;DR

This paper investigates how quantum entanglement of biphotons influences two-photon absorption in semiconductor quantum wells, revealing that entanglement enhances absorption and can serve as a sensitive probe of photon correlations.

Contribution

It demonstrates the dependence of two-photon absorption on biphoton entanglement and explores how quantum correlations affect excitonic absorption in quantum wells.

Findings

Entangled photons significantly increase exciton oscillator strengths.

Two-photon absorption is highly sensitive to biphoton quantum correlations.

Comparison shows different absorption behaviors for frequency-anti-correlated, unentangled, and frequency-correlated biphotons.

Abstract

The dependence of the excitonic two-photon absorption on the quantum correlations (entanglement) of exciting biphotons by a semiconductor quantum well is studied. We show that entangled photon absorption can display very unusual features depending on space-time-polarization biphoton parameters and absorber density of states for both bound exciton states as well as for unbound electron-hole pairs. We report on the connection between biphoton entanglement, as quantified by the Schmidt number, and absorption by a semiconductor quantum well. Comparison between frequency-anti-correlated, unentangled and frequency-correlated biphoton absorption is addressed. We found that exciton oscillator strengths are highly increased when photons arrive almost simultaneously in an entangled state. Two-photon-absorption becomes a highly sensitive probe of photon quantum correlations when narrow semiconductor quantum wells are used as two-photon absorbers.