Molecular states observed in a single pair of strongly coupled self-assembled InAs quantum dots

T. Ota, M. Stopa, M. Rontani, T. Hatano, K. Yamada, S. Tarucha, H. Z. Song, Y. Nakata, T. Miyazawa, T. Ohshima, N. Yokoyama

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5 Citations (Scopus)


Molecular states in a single pair of strongly coupled self-assembled InAs quantum dots are investigated using a sub-micron sized single-electron transistor containing just a few pairs of coupled InAs dots embedded in a GaAs matrix. We observe a series of well-formed Coulomb diamonds with charging energy of less than 5 meV, which are much smaller than those reported previously. This is because electrons are occupied in molecular states, which are spread over both dots and occupy a large volume. In the measurement of ground and excited state single-electron transport spectra with a magnetic field, we find that the electrons are sequentially trapped in symmetric and anti-symmetric states. This result is well explained by numerical calculation using an exact diagonalization method.

Original languageEnglish
Pages (from-to)159-164
Number of pages6
JournalSuperlattices and Microstructures
Issue number3-6
Publication statusPublished - Sep 1 2003
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

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