“You need another gate, mate”: g-factor engineering in quantum wires and wrap-gated nanowires

Electrostatically gated AlGaAs/GaAs quantum wires and InAs nanowires are two common platforms for studying 1D electron physics. Quantum wires are typically defined using a splitgate structure on an AlGaAs/GaAs heterostructure. Nanowires are typically gated from below by a heavily doped Si substrate. The level of control is limited in these heavily-studied, traditional device designs. Advancements in nanofabrication make it possible to implement more sophisticated gating schemes, enabling improved control over 1D devices. We will discuss our recent work on 1D electron devices with more advanced density control. We start firstly with the possibility of engineering the g-factor in top-gated quantum wires for spintronics applications [1], and then discuss our work on using wrap-gates to improve density control in InAs nanowires.