Berlin 2018 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 20: Focussed Session: Geometry- and Topology-Controlled Nanoarchitectures II

HL 20.1: Vortrag

Dienstag, 13. März 2018, 14:00–14:30, EW 015

Optical Aharonov-Bohm oscillations with disorder effects and Wigner molecule in a single quantum ring — •Kwangseuk Kyhm — Pusan National University, Busan, South Korea

The Aharonov-Bohm (AB) effect is observed mostly by electrical measurements at extremely low temperatures (<100 mK) through oscillations of the conductance and persistent current with external magnetic field. Very recently, the AB effect became accessible to optical experiments at tens of Kelvin by using type-II quantum dots (QDs) and quantum rings (QRs) in ensembles. However, the exciton Aharonov-Bohm oscillations in a single QR are rarely observed. This difficulty is associated with disorder effects. In the presence of structure anisotropy, localisation, in- ternal electric field, and impurity scattering, we found that optical Aharonov-Bohm oscillations of an electron-hole pair become modulated. Additionally, provided that a strongly correlated exciton pair is formed in a single quantum ring similar to the Wigner molecule, novel oscillations can be observed for increasing magnetic field. In this case, the biexciton emission energy changes abruptly at transition magnetic fields with a fractional oscillation period compared to that of the exciton, the so-called fractional optical Aharonov-Bohm oscillations.