03. Noise characteristics of 100 nm scale GaAs/Al x Ga 1-x As scanning Hall probes

The authors have fabricated and characterized GaAs/AlxGa1−xAs Ga As ∕ Al x Ga 1 − x As two-dimensional electron gas scanning Hall probes for imaging perpendicular magnetic fields at surfaces. The Hall crosses range from 85×85to1000×1000nm2 85 × 85 to 1000 × 1000 nm 2 . They study low-frequency noise in these probes, especially random telegraph noise, and show that low-frequency noise can be significantly reduced by optimizing the voltage on a gate over the Hall cross. The authors demonstrate a 100nm 100 nm Hall probe with a sensitivity of 0.5G/√Hz 0.5 G ∕ √ Hz (flux sensitivity of 0.25mΦ0/√Hz 0.25 m Φ 0 ∕ √ Hz ; spin sensitivity of 1.2×104μB/√Hz 1.2 × 10 4 μ B ∕ √ Hz ) at 3Hz 3 Hz and 9K 9 K .