Resonant magnetotunneling through individual self-assembled InAs quantum dots

Resonant peaks are observed in the low-temperature current-voltage I(V) characteristics of a single-barrier GaAs/AlAs/GaAs diode with InAs quantum dots incorporated in the AlAs tunnel barrier. We argue that each peak arises from single-electron tunneling through a discrete zero-dimensional state of an individual InAs dot in the barrier. Each peak splits into sharp components for magnetic field B parallel to I; the I(V) curve probes the density of Landau-quantized states in the emitter-accumulation layer. A dot size of approximate to 10 nm was estimated from the diamagnetic peak shift for B perpendicular to I.