The authors present low temperature transport measurements on double quantum dots in InAs nanowires grown by metal-organic vapor phase epitaxy. Two dots in series are created by lithographically defined top gates with a procedure involving no extra insulating layer. The authors demonstrate the full tunability from strong to weak coupling between the dots. The quantum mechanical nature of the coupling leads to the formation of a molecular state extending over both dots. The excitation spectra of the individual dots are observable by their signatures in the nonlinear transport.

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In this measurement, a charge rearrangement affecting only GR shifted the necessary gate voltage on the right gate by approximately 150mV compared to Fig. 2. The center gate, which determines the interdot coupling, has not been changed.

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