Figure 3: Measurement setup and physical properties of the InGaAs-based QPC device.
From: Spin–orbit induced electronic spin separation in semiconductor nanostructures
(a) The trench-type QPC device with top- and side-gate electrodes. The trench and surface of the device are covered with an Al2O3 insulator. Although the top gate is not drawn around the QPC region for the clarity of the side gates, a Cr/Au top gate covers the entire QPC region in the real device. (b) Effective magnetic field Beff as a function of sheet carrier density in an InGaAsP/InGaAs two-dimensional electron gas at T=0.3 K. (c) Electron mean free path and mobility as a function of sheet carrier density in an InGaAsP/InGaAs two-dimensional electron gas at T=0.3 K. The red circles and blue circles are the electron mean free path and the mobility with the left and right axes, respectively. (d) Calculated potential landscape in an InGaAsP/InGaAs-based QPC. The potential structure is spatially modulated along the conducting channel due to the side gates. (e) Calculated effective magnetic field Beff along the y direction at x=106 nm.
