Aharonov–Bohm effect in nanoscale quantum rings fabricated from compensating-layer GaAs/AlGaAs heterostructures

Nanoscale devices are fabricated from modulation-doped GaAs/AlGaAs heterostructures, where the two-dimensional electron system is initially depleted. Upon removing the p-type capping layer that compensates for the n-type supply layer, the electron system is induced. Aharonov–Bohm (AB) loops of 110 and View the MathML source diameter (average) and View the MathML source width and conducting areas as leads are formed by patterning a thin resistant layer with an atomic force microscope and subsequent selective wet etching. At View the MathML source and under perpendicular magnetic field the differential conductance of the AB loops exhibits an oscillatory pattern imposed on a smoothly varying background. The AB oscillation period of View the MathML source corresponds well to the geometric dimension of the small (large) ring.