Publications associated with Semiconductor Materials, Devices & Nanostructures

Light Controlled Optical Aharonov-Bohm Oscillations in a Single Quantum Ring.

Nano letters 18 (2018) 6188-6194

H Kim, S Park, R Okuyama, K Kyhm, M Eto, RA Taylor, G Nogues, LS Dang, M Potemski, K Je, J Kim, J Kyhm, J Song

We found that optical Aharonov-Bohm oscillations in a single GaAs/GaAlAs quantum ring can be controlled by excitation intensity. With a weak excitation intensity of 1.2 kW cm-2, the optical Aharonov-Bohm oscillation period of biexcitons was observed to be half that of excitons in accordance with the period expected for a two-exciton Wigner molecule. When the excitation intensity is increased by an order of magnitude (12 kW cm-2), a gradual deviation of the Wigner molecule condition occurs with decreased oscillation periods and diamagnetic coefficients for both excitons and biexcitons along with a spectral shift. These results suggest that the effective orbit radii and rim widths of electrons and holes in a single quantum ring can be modified by light intensity via photoexcited carriers, which are possibly trapped at interface defects resulting in a local electric field.

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