We used focused ion beam insulation writing to fabricate quantum point contacts in the two-dimensional electron gas of an InGaAs/lnAlAs heterostructure. The conductance as a function of voltage on an adjacent in-plane gate exhibited steps for temperatures up to 60 K. From the temperature and source-drain voltage and magnetic field dependence of the conductance steps, we estimated the one-dimensional subband spacing to be 15 meV.
- Focused ion beam
- In-plane gate
- InGaAs/lnAIAs heterostructure
- Insulation writing
- Quantized conductance