Focused ion beam patterned Hall nano-sensors

By means of focused ion beam milling, we fabricate Hall magnetometers with active areas as small as 100 × 100 nm2. The constituent material can either be metallic (Au), semimetallic (Bi) or doped bulk semiconducting (Si doped GaAs). We experimentally show that Au nano-probes can work from room temperature down to liquid helium with magnetic flux sensitivity < 10- 1 Φ0. © 2006 Elsevier B.V. All rights reserved.