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Voltage-Controlled Optics of a Quantum Dot

A. Högele·S. Seidl·M. Kroner·K. Karrai·R. J. Warburton·B. D. Gerardot·P. M. Petroff
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Abstract

We show how the optical properties of a single semiconductor quantum dot can be controlled with a small dc voltage applied to a gate electrode. We find that the transmission spectrum of the neutral exciton exhibits two narrow lines with $\sim 2$ $μ$eV linewidth. The splitting into two linearly polarized components arises through an exchange interaction within the exciton. The exchange interaction can be turned off by choosing a gate voltage where the dot is occupied with an additional electron. Saturation spectroscopy demonstrates that the neutral exciton behaves as a two-level system. Our experiments show that the remaining problem for manipulating excitonic quantum states in this system is spectral fluctuation on a $μ$eV energy scale.

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A. Högele, S. Seidl, M. Kroner, K. Karrai, R. J. Warburton, B. D. Gerardot, P. M. Petroff. 2004-11-25. Voltage-Controlled Optics of a Quantum Dot. https://doi.org/10.1103/physrevlett.93.217401

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