Coherent and robust high-fidelity generation of a biexciton in a quantum dot by rapid adiabatic passage

TL;DR

This paper demonstrates a highly coherent and robust method for generating biexcitons in quantum dots with near-perfect fidelity using rapid adiabatic passage, overcoming limitations of previous techniques.

Contribution

The study introduces the application of rapid adiabatic passage for biexciton generation in quantum dots, achieving near-unity fidelity and robustness against experimental variations.

Findings

Achieved biexciton generation with fidelity close to one.

Validated results with microscopic phonon-coupled simulations.

Showed robustness of the method against experimental parameter fluctuations.

Abstract

A biexciton in a semiconductor quantum dot is a source of polarization-entangled photons with high potential for implementation in scalable systems. Several approaches for non-resonant, resonant and quasi-resonant biexciton preparation exist, but all have their own disadvantages, for instance low fidelity, timing jitter, incoherence or sensitivity to experimental parameters. We demonstrate a coherent and robust technique to generate a biexciton in an InGaAs quantum dot with a fidelity close to one. The main concept is the application of rapid adiabatic passage to the ground state-exciton-biexciton system. We reinforce our experimental results with simulations which include a microscopic coupling to phonons.