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arXiv · 0705.3962

Mapping electron delocalization by charge transport spectroscopy in an artificial molecule

M. R. Graeber·M. Weiss·D. Keller·S. Oberholzer·C. Schoenenberger
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Abstract

In this letter we present an experimental realization of the quantum mechanics textbook example of two interacting electronic quantum states that hybridize forming a molecular state. In our particular realization, the quantum states themselves are fabricated as quantum dots in a molecule, a carbon nanotube. For sufficient quantum-mechanical interaction (tunnel coupling) between the two quantum states, the molecular wavefunction is a superposition of the two isolated (dot) wavefunctions. As a result, the electron becomes delocalized and a covalent bond forms. In this work, we show that electrical transport can be used as a sensitive probe to measure the relative weight of the two components in the superposition state as a function of the gate-voltages. For the field of carbon nanotube double quantum dots, the findings represent an additional step towards the engineering of quantum states.

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M. R. Graeber, M. Weiss, D. Keller, S. Oberholzer, C. Schoenenberger. 2007-05-27. Mapping electron delocalization by charge transport spectroscopy in an artificial molecule. https://doi.org/10.1002/andp.200710256

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