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Single-Electron Transistor Spectroscopy of InGaAs Self-Assembled Quantum Dots



Kevin Osborn, Mark W. Keller, Richard Mirin


A single-electron transistor is used to detect tunneling of single electrons into self-assembled InGaAs quantum dots. Aluminum single-electron transistors (SETs) are fabricated over an MBE-grown structure containing quantum dots (QDs) and an underlying n-doped layer. By using a SET with a small island area (2 × 10-2 υm2), and growing QDs with an appropriate density (1 × 1010 cm2), we are able distinguish and measure three QDs. At specific voltages applied to the n-doped layer and gate, a single electron is tunneled into a QD. The SET detects two tunneling events per dot, depend on the Coulomb interaction and the energy of the unoccupied electron level. Capacitances to the QD are extracted. The single-electron spectrum is compared to conventional capacitance spectroscopy results on the same wafer, which measures a large ensemble of QDs.
Physica E-Low-Dimensional Systems & Nanostructures


quantum dot, single-electron transistor, InGaAs, self-assembled


Osborn, K. , Keller, M. and Mirin, R. (2004), Single-Electron Transistor Spectroscopy of InGaAs Self-Assembled Quantum Dots, Physica E-Low-Dimensional Systems & Nanostructures, [online], (Accessed April 16, 2024)
Created December 31, 2003, Updated October 12, 2021