Trion quantum coherence in site-controlled pyramidal InGaAs quantum dots

TL;DR

This paper demonstrates the coherent control of trion states in site-controlled pyramidal InGaAs quantum dots, showing their potential as scalable platforms for quantum information processing by revealing ultrafast quantum coherence similar to other quantum dot systems.

Contribution

It introduces the coherent manipulation of trion states in pyramidal quantum dots and shows their suitability for scalable quantum information applications.

Findings

Observation of fourfold splitting of charged excitons in magnetic fields

Ultrafast complete coherent control of trion to ground state transition

Quantum coherence times comparable to other quantum dot platforms

Abstract

Deterministically positioned pyramidal InGaAs quantum dots (QDs) exhibit exceptional quantum properties, making them highly promising candidates for scalable on-chip quantum information processing. In this work, we investigate the coherent dynamics of positively charged excitons under the influence of strong magnetic fields in the Faraday configuration. Pyramidal quantum dots exhibit a fourfold splitting of the charged excitons even in the Faraday configuration, giving rise to an optically addressable double-Lambda{\Lambda} system akin to self-assembled quantum dots in oblique magnetic fields. Here, we investigate ultrafast complete coherent control of the trion to ground state transition utilizing advanced optical resonant excitation techniques and we observe quantum coherence over timescales that are similar to other prominent quantum dot platforms. These results pave the way towards establishing site-controlled pyramidal InGaAs QDs as scalable platforms for quantum information processing, expanding the reach of coherent control to new quantum systems.