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HL: Fachverband Halbleiterphysik

HL 23: Quantum dots and wires: Transport properties I

HL 23.3: Vortrag

Dienstag, 26. Februar 2008, 11:30–11:45, EW 201

Room temperature memory operation of an in-plane quantum-wire transistor with embedded quantum dots — •Christian R. Müller, Lukas Worschech, Jan Heinrich, Sven Höfling, and Alfred Forchel — Technische Physik, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany

Memory operation of an in-plane gated quantum-wire transistor with embedded quantum dots is demonstrated at room temperature. The quantum-wire transistor is realized by electron beam lithography and wet chemical etching on the basis of a GaAs/AlGaAs heterostructure with self-assembled InAs quantum dots. Room temperature memory operation of the quantum dots was observed, when they were positioned approximately in the center of a Si-doped AlGaAs spacer, where the conduction band shows a minimum. The charge state of the quantum dots is read out by transport measurements with the threshold voltage of the quantum wire reflecting the charge state. The memory operation is due to a pronounced charging and discharging of the quantum dots which is achieved by sweeping up and down the gate voltage at the electrically isolated side gates. In such quantum-wires, threshold hysteresis of a few 100 mV is observed at room temperature.