Light controlled optical Aharonov–Bohm oscillations in a single quantum ring

Journal article

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.

Authors: Kim, H; Park, S; Okuyama, R; Kyhm, K; Eto, M

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: Nano Letters
• Volume: 18
• Issue: 10
• Pages: 6188–6194
• Publication date: 2018-09-18
• Acceptance date: 2018-09-18
• DOI: 10.1021/acs.nanolett.8b02131
• ISSN: 1530-6984
• Keywords: Aharonov−Bohm effect; photoluminescence; light excitation; excitons; quantum rings