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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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Abstract

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 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.

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T. Ota, M. Stopa, M. Rontani, T. Hatano, K. Yamada, S. Tarucha, H. Z. Song, Y. Nakata, T. Miyazawa, T. Ohshima, N. Yokoyama. 2004-01-28. Molecular states observed in a single pair of strongly coupled self-assembled InAs quantum dots. https://doi.org/10.1016/j.spmi.2004.03.003

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