A fabrication technique for quantum point contacts (QPCs) in an InGaAs/InAlAs two-dimensional electron gas heterostructure is reported. The key challenge in realizing a well-behaved QPC is efficient electrostatic control of a one-dimensional channel using the gate electrode. The fabricated QPCs employ a 100-nm-wide mesa constriction and a gate electrode that wraps around the constriction for three-dimensional electricfield gating. In addition, conformal aluminum-oxide growth by atomic layer deposition is employed to suppress gate leakage while minimizing the interface state density. The wrap-gate QPCs show clear conductance steps, demonstrating well-defined quantized transverse modes in the InGaAs-based one-dimensional channel.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)