Self-aligned charge read-out for InAs nanowire quantum dots

I. Shorubalko , R. Leturcq (1) , A. Pfund , D. Tyndall , R. Kischek , S. Schön , K. Ensslin

1 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520

A highly sensitive charge detector is realized for a quantum dot in an InAs nanowire. We have developed a self-aligned etching process to fabricate in a single step a quantum point contact in a twodimensional electron gas and a quantum dot in an InAs nanowire. The quantum dot is strongly coupled to the underlying point contact which is used as a charge detector. The addition of one electron to the quantum dot leads to a change of the conductance of the charge detector by typically 20%. The charge sensitivity of the detector is used to measure Coulomb diamonds as well as charging events outside the dot. Charge stability diagrams measured by transport through the quantum dot and charge detection merge perfectly.

Domaines: Physique [physics]

I. Shorubalko, R. Leturcq, A. Pfund, D. Tyndall, R. Kischek, et al.. Self-aligned charge read-out for InAs nanowire quantum dots. Nano Letters, 2008, 8, pp.382-385. ⟨10.1021/nl072522j⟩. ⟨hal-00357379⟩