Magnetotransport On Evenly Curved Hall-Bars In InGaAs/GaAs-Microtubes

摘要

We present transport measurements on evenly curved two dimensional electron systems in Hall-bar geometry. By combining the method of self-rolling strained double-layers with a special lithographic procedure we are able to roll-in and contact AlGaAs/GaAs/AlGaAs quantum well structures into tubes or curved lamellas. Applying a magnetic field to such structures results in a sinusoidal modulation of the magnetic field components perpendicular to the curved 2 DES plane. Transport measurements with current direction parallel to the rolling axis exhibit weak oscillations reflecting the superposition of magneto oscillations caused by different perpendicular magnetic field vectors. In contrast to this, magneto transport along the curvature of the tubes shows pronounced Shubnikov-de Haas oscillations which can be associated with the maximum perpendicular magnetic field component between the contacts. Furthermore, a breakdown of magnetic field inversion symmetry depending on the perpendicular field component distribution along the curved Hall-bar is observed.