Formation and control of a correlated exciton two-qubit system in a coupled quantum dot

Keishiro Goshima, Kazuhiro Komori, Takeyoshi Sugaya, Toshihide Takagahara

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


We have proposed the basic device structures for an all-optical controlled two-qubit quantum logic gate using two excitons confined in InAs/GaAs coupled quantum dots (CQDs). A two-qubit quantum logic gate is constructed using a correlated two-exciton system. This simplest two-qubit system involves four states such as the crystal ground states, two distinguishable exciton states, and a correlated-exciton-molecule state consisting of two excitons. The formation of this correlated-exciton-molecule state, which consists of two different excitons in a CQD, is the most important and difficult technology. In this study, we demonstrate the formation of the four states involving this correlated-exciton-molecule state and confirm two-qubit exciton system in CQDs. Moreover, we show that a correlated exciton molecule is created by employing a cascade process.

Original languageEnglish
Article number205313
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number20
Publication statusPublished - 2009 May 1

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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